Gah, Nippy...you're batting zero today.

The fact that Sorceror's are limited in the spells they can cast is all the more reason to lean towards a certain area, so they can study spells of that type. For instance, a young sorceror grows up in a country side continually ravaged by bandits. Perhaps they burn down his home and he develops an intense hatred towards them and wants nothing more than to hunt down and kill every last man. He would prolly lean towards desctructive spells.
Now say you have an young Empress that is thrown into politics at an early age. She discovers she has magical abilities, and these abilities can be used to sway those she dictates or negotiates with. She might very well work with dominating and mind-controlling spells.
Or what about the servant and protector to this Empress. He might harness his powers towards protecting his Empress.
Basically, Midnight, I think you should, as you develop your character's background and personality, think on why he/she is studying protective and illusionary spells. Sorcerors have a tremendous innate power, and something is going to determine how they use that power. What is it for your character? That's a rhetorical question, by the way.

Totino's party pizzas rock! All a college kid needs to get by....