[Toomuch]

Like many people have stated in other words, a lot of this has to do with a few key variables:

1. Is this person going to be soloing, or are they are going to be grouping? Or some of both?

2. Is this person starting 100% from scratch, with absolutely no gear at all? Or are they at least going to be given some basic armor/weapons and stuff? Or will they be a full twink?

3. What level of skill/adaptability does this person have? Is this person your grandma, who has never played a video game in her life? Or is this person a long-time gamer?

If this person is planning on soloing, and will have absolutely no gear to start out with at all, I'd say most difficult would be Rogue, then Warrior, then maybe Paladin or Ranger.

If this person is planning on soloing, and will be fully twinked out, then Warrior might actually be one of the easiest classes to pick up on, but even easier long-term will be someone with more survival tools like a shadowknight or monk, who also are relatively easy to pick up on. A fully twinked int/wis caster class will still get steamrolled if they are having a hard time on the uptake with all the mechanics.

If this person is planning on grouping, and will have absolutely no gear to start out with, the easiest would be any class with a very straightforward/simple role, like a healer or nuker - they can just stand/sit there and do their one job. Hardest might be a pulling class, CC class, or possibly even tanking class if they are less savvy with games.

If this person is planning on grouping, and will be twinked out, then just about any class will probably work, but I'd still say a CC/utility role is probably the hardest for a newbie, and any DPS is probably the easiest, with maybe Mage at the top of that list.

Finally, if you are planning on Duoing with this person, I'd suggest you (the more savvy person) be an enchanter, and the newbie friend guy be a Druid.