What is the easiest class/spec for beginners?

[Val the Moofia Boss]

Druids and mages; Mages are the best for learning how to play, druids allow you to decide what role you like to play and how the game's mechanics work.

[Phasma]

A hybrid class for sure. You want to expose a new player to all the possible roles so they can choose which one they would enjoy most.