Originally Posted by
Kazela
SMN: Affliction warlock w/ tank pet, or choice of dps pet (one being ranged, other melee)
DRG: Kinda-sorta like rogue, minus stealth (I only have experience with DRG up to 50 though)
WAR: Tank, more akin to WoW's Death Knight if anything
PLD: Similar (but yet very different) than WoW's prot paladin.
Each class has a story from 1-30. Once the level 30 class quest is completed (and you've leveled up the necessary secondary class), the job quests become available. Once you decide on which you want to focus on, make sure to check into which secondary class you need. Eventually, you'll find a need to level a bit of everything for various cross class skills that are pretty much must haves. Examples: leveling up gladiator to 16 or 18...whatever level they get Provoke. Thaumaturge/Black Mage for Swiftcast, etc.