Poison Arrow is great at the start of the game; I have not tried Stun Arrows yet (wasn't really planning to), but others have reported quite positive results. At a higher level Explosive Arrows will likely replace everything else except Splitting Arrows (AFAIK this is quite effective, especially at close range, where most or all of the arrows will hit a single target).
I've posted comments about my level 2 ranger in the topic
Who's playing DKS on nightmare difficulty ?If you play a mage, you get the bonus from any magic damage enchantments to your weapons applied to your spells. Also, if you use magic based weapons, they get a boost from intelligence, so you can be relatively effective at melee combat if you need to be. You would not need to invest any skill points in Duel Wield Expertise to get the full magic damage bonus for your spells, since the off hand penalty isn't used for that.
