just play around with your first character, because you are 100% guaranteed to screw it up before level 20. Have fun with him, but don't expect him to make it to hell difficulty.
I actually just posted a druid guide, which I painstakingly drew out what particular items used for the druid (its a shapeshifter) for end game. It might give you an idea of what a successful build will look like.
Umm, other than that, make sure you check out the arreat summit, the official online guidebook for diablo 2. You can also read up on some of the fansites, such ass diii, which have some really good guides that break down the mechanics of the game (such as tables on faster hit recovery or attack speed.) They go well beyond what the lying character screen tells you.