If you are just starting, the simpler the better.
The D&D games can get complex with multiple side quests, etc., except for Icewind Dale which is, as said, fairly linear.
My wife eased her way into RPG's with Might & Magic 6 (the better of the latest 3, IMHO).
If you have any consoles, some console RPG's might be a good place to start as well. Final Fantasy IX is fairly easy to learn, but is addicting and fun.
Hope this helps. =)
PS - Icewind Dale has an expansion coming out next month as well. =D