I just get Mog first thing for his nice little Moogle Charm.
I'm a horrible, horrible, person.
Edit: Xurts, I usually beat the game with those levels, so don't worry too much about power leveling in this game. Well, unless you like having high levels which is understandable.
This is the magic you should give priority to in WoB:
Cure
Cure 2
Life
Antdot
Remedy
Regen
Fire
Fire 2
Ice
Ice 2
Bolt
Bolt 2
Drain
Osmose
Yeah, I would like to have my levels around 50 when I go to Kefka's Tower. I plan I doing all of the sidequests and everything so I will probably need those levels for the Dino Forest and the Tower of Fanatics, at least.
Peter_20, Osmose is definately one of the first you should learn. Osmose is a huge help, and one of the main reasons why my party is always full of mages.