IIRC, the number of spells you can prepare per day is equal to the number of "spells per day".
http://paizo.com/pathfinderRPG/prd/classes/wizard.html
See "spells per day" progression in Table: Wizard.
I put this up on another forum, but I want to capture a greater range of opinions, so I've decided to post here too. Anywho, I basically summarised the frame of the class below for quick and easy reading. Could I please have your thoughts on how to balance it against the core and base classes...
Oracle with the Bones mystery.
Charismatic?
Yes! The oracle's main stat is Charisma.
Able to talk your way out of sticky situations?
Yes! Bluff, Diplomacy and Intimidate are all class skills, and the oracle's main stat is Charisma.
Spellcaster?
Yes! No need for explanation here, I don't...