Tier 1
Tier 1 overview
Militia & 
Natural Philosophy should always be the starting technologies. If there are salvage sites near your starting location it should be dismantled as soon as possible as it may contain Tomes of Knowledge.
Next, economic technologies 
Cast-iron axe blades and 
Stonecutting, which improve the speed of resource gathering needed for construction and also speed up the clearing of areas for new buildings.
After this you can unlock 
Taxation, but not until you’ve built a market (one Tome of Knowledge will be obtained once the market is ready).
Woodlore - the usefulness of this technology depends on the map. There’s no need to pick it up early if there are no good gathering spots on the map.
However, in a good clearing, with this technology, one forager can gather up to 500 units of food per year. Woodlore is followed by 
Trailblazing. The usefulness of these technologies increases with the number of hunters and foragers in your settlement. The value of Woodlore also increases dramatically with the Forager’s hut upgraded to tier 2.
Sustainable fishing is only useful if your map has a lot of lakes.
Sustainable farming is only worth unlocking if you’re already growing greens or root vegetables. Early stages of farming typically involve growing beans, which don’t reduce soil fertility, so this technology will be useless. You’ll only need it to develop 
Disease resistance.
As your population grows in non-pacifist mode 
Defensive barricades will be very useful. Starting in Year 6, reinforced raids with Shield Bearers may arrive, and with a large population (more than 60), these raids will also be numerous, capable of destroying your town center. Barricades will help your town center survive.
Hygiene - research only if your villagers frequently fall ill. Usually needed as you approach 100 settlers and if soap production is difficult due to the lack of herbs on the map.
Production logistics & 
Adjustable shoe lasts are useless in the early stages of the game, but they can be researched once your settlement has grown significantly.
Iron shares - I still don’t know what exactly this technology affects. In any case, its effectiveness increases with the number of farmers, so in the early stages, it would be a waste of a Tome of Knowledge. (If this technology affects field construction speed, then it might be more useful in the early stages of the game.)
Venting chambers. I find this technology completely useless. Smokers spend most of their time transferring raw product to the smokehouse, and the smoking process itself takes at best half the time. It’s better to add an additional smoker than to waste a valuable Tome of Knowledge on this technology.
Spotters. You don’t need this. If you need visibility on the map, build and deactivate hunter cabin or forager hut.
Tier 2
Tier 2 overview
Forestry and its predecessor 
Silviculture are among the most important at tier 2. Your growing settlement requires ever more logs and the sooner you establish a steady supply of logs the better. If the map is rich in forests you can postpone researching these technologies until you begin to feel a pressing need for logs, but I prefer and recommend building at least one Forester Camp as early as possible. Under good conditions, a single Forester Camp can provide a very large supply of logs per year - from 300 to 600. You can also add a couple of regular worker camps to the area where foresters plant trees, which will increase log production in that area.
Scientific method - unlock at the same time as the academy is ready.
Stiff-blade saw. Planks are required for a large number of second-tier settlement buildings.
Arms production.The technology is essential for a non-pacifist mode. It would be a good idea to equip four light infantry with hauberks and shields by Years 7-8. This will be enough to clear out bandit camps on the map and fend off most raids. Coal and iron for production can be purchased at the market - it only takes 48 iron and 16 coal to produce four hauberks. In extreme cases, you’ll have to research 
Mining to extract coal and iron ore, and 
Forging to smelt iron. But then you’ll have to buy one set of heavy tools for a forge.
Forging and Mining are useful technologies in any case and along with 
Smithing will be essential for your settlement in the future. But don’t rush into researching them. First you need to ensure you have sufficient work force.
Soldier training is another important technology for increasing military might. It requires two Tomes of Knowledge and is best unlocked immediately before researching 
Siege shields, which significantly increases the survivability of your infantry. However, Siege Shields is a Tier 3 technology and requires 24 Knowledge points, so Soldier Training should be researched using Tomes 23 and 24, and Tome 25 should be used for Siege Shields. After that, you can arm four light infantrymen and clear out bandit camps.
Disease resistance. Be sure to research this if you are already involved in farming.
Animal husbandry. Before researching this technology, you should do your homework: you’ll need resources to build a barn, as well as gold to buy livestock. It’s best to buy four cows or four goats at a time to guarantee offspring. Therefore, you’ll need 3,600 gold for cows and about 2,000 for goats. There’s no point in researching this technology if you don’t already have these resources. Chicken coops will be needed later in the game to produce eggs needed for pastries.
Nursing. There is also no need to rush into researching this technology. Maintaining a Healer’s House is quite expensive. I understand your desire to save wounded villagers, but building a Healer’s House too early can significantly slow down your settlement’s development. However, it’s always useful to have a Tome of Knowledge and resources in reserve so you can quickly build a Healer’s House in case of emergency. Furthermore, the Healer’s House can be deactivated, using it only to save the wounded.
Architecture. This technology will not only speed up the construction of buildings, but also open the way to the Tier-3 
Masonry technology, which will save you a large amount of bricks both later and in the early stages of the game, when you can only find bricks in ruins or buy them from merchants.
Grain crops. Grain is necessary for the production of bread, and we need bread to increase the variety of food in houses, for their subsequent improvement to large houses, that is, before moving on to tier 4 settlement.
Paper press. You might think I’ve rated this technology too low, since we need paper production to speed up the research of new technologies. However, the cost of this production is quite high – it requires flax and the building itself requires bricks. It’s easier to just buy the required volumes of paper from merchants for now. But even without paper, the rate of knowledge accumulation at this stage is quite satisfactory. In my opinion, it’s best to start paper production at Tier 4.
Productivity-enhancing technologies are only worth considering if you’ve already built up sufficient production volumes for the relevant technology:
Artificial selection, 
Heavy freight wagons, 
Treadwheel crane, 
Double walled hives
Tier 3
Tier 3 overview
I described the Siege Shields and Masonry technologies in the previous section.
Two more key technologies from Tier 3 are 
Scientific discovery, which increases the speed of acquiring new knowledge, and 
Trade center, which attracts an additional merchant annually, thereby expanding our trading capabilities.
Advanced metal casting increases the durability of tools and heavy tools, which are crucial for the development of heavy industry, and we are just reaching the stage where heavy industry is becoming the core business of our community. Therefore, 
Production management is also of interest to us.
Commerce negotiations is also a very useful technology. Production is expanding, and we have a surplus of products that we’d like to sell to merchants. The policy opened by this technology will allow us to make a lot of money by selling the excess product.
A growing population requires ever-increasing amounts of food, so it’s crucial to focus on developing the agricultural sector. 
Selective breeding: non-grain will increase the yield of non-grain crops, while 
Vermicast will boost compost production, which in turn improves field fertility.
You’ll likely already have a barn or two at this stage, so 
Animal rearing will be useful for increasing your herd size.
Caseiculture will help us reduce the spoilage of milk. However, if the volume of spoiled milk is still insignificant, there’s no need to rush into exploring this technology.
Cavalry and 
Military logistics will allow you to begin breeding horses to arm your cavalry units later on, and will also reduce the cost of recruiting and maintaining armies. This will be useful whether you plan to constantly maintain an army or only recruit troops during raids.
The second method is generally cheaper, but then you may need technology from the Tier-2 
Command structure, thanks to which your troops will gain experience faster and become stronger directly during battles.
Below I will highlight some other technologies that I considered less important, but still significant.
Hospitalization and 
Variolation - reduce the risk of epidemics. Building a hospital isn’t necessary - additional healer’s houses can be built instead, but it’s important to have a reserve of hospital beds in case of epidemics. To achieve this, activate reserve healer’s houses only if the number of infected villagers increases.
Glass blowing and 
Canning - preserving fruits and vegetables allows you to build up a substantial food supply. However, this production chain requires a significant amount of labor, so it may be overkill unless you have a significant problem with spoilage. It’s more suitable for Tier 4 settlements.
The military technologies 
Tools of war and 
Reinforced plating will allow you to produce weapons for heavy infantry, which will gradually replace light infantry in your army. Light infantry hauberks can be given to archers after researching 
Brigandine armor, increasing their survivability, while 
Wheel-lock crossbows will increase their damage.
Furthermore, weapon production can require significantly larger amounts of iron, so
Metallurgy and 
Blast furnace will be also useful.
Tier 4
Tier 4 overview
The School of Thought will allow you to upgrade the Academy to the Grand Academy, which can accommodate 12 scientists. However, this upgrade requires 50 glassware, so purchase it first or set up production using the Glass Blowing technology.
Important military technologies: 
Citadels allow you to upgrade Barracks to Forts (this also requires the Tier 2 
Arrow Loops technology), and 
Conscription unlocks the policy of the same name, which provides a discount on troop recruitment. Citadels should be researched around the same time as the Tier 3 technologies Tools of War and Reinforced Plating, so you can produce equipment for pikemen and heavy infantry yourself, which can be recruited from Forts.
Guilds unlock the ability to build the Guild Hall, which allows you to focus your efforts on one aspect of production, optimizing your economy.
Favored nation, 
Fire assaying, 
Selective breeding: grains improve your trading, gold ingots and grain production.
Intensive animal farming opens up the policy of the same name that boosts meat production at the expense of livestock health, but if you have good pastures, these policies can be sustainable.
Rehabilitation significantly increase the recovery rate of your patients.
Monuments
Economic Power. The Economic Monument is deservedly considered the most useful. It significantly expands your storage capacity, and visiting merchants are willing to buy significantly more products from you, sometimes coming with special requests at very favorable prices.
Beacon of Culture. The Civic Monument comes in second place. The additional decorations and building construction and relocation speed boost are just the thing once your settlement is sufficiently developed and it’s time to turn it into a gem.
Gates of Valor. The War Monument doesn’t provide any special benefits other than extra experience for your soldiers. But it’s still useful, especially if you’re playing in Peaceful mode and want to spice things up by challenging the invaders.
I’d like to highlight 
Border Policies technology separately. It becomes available once your settlement is already quite large, so there’s little point in using it, but if you’re planning to build a settlement for several thousand residents and your hardware capacity allows for it, then feel free to research this technology.
