Also never played D3 for more than a minute. There are some exquisite nuances to how damage / armor/ resistance are calculated in this game - for instance some of the hightest dps builds in the game are based solely on retaliation damage. However I would second the notion that your first playthrough should be pretty virgin for the experience alone (like any new game.) Once you’ve gotten a feel for how a build might be optimized you can refer here for other ideas – Build Compendium X (Forgotten Gods).