@swordpath, when you mouse over things they tell you what things they'll improve. So something with +dexterity will say +damage in green when you mouse over it in your inventory. You have to decide for yourself whether damage trumps life, etc though.
The extra stuff I've been mostly salvaging since it doesn't really sell for much. Also found out that stash and gold is shared between characters you own, which is a little odd but should make it super easy to trick out future low level guys - haven't looked into that yet myself. I'm using all my gold to upgrade my artisans for now, since buying stuff is probably a waste of money at this level.