Alright, there's skills that each class is good at, and one's each class is prohibited from, and skills each class can take, but it costs twice as much to use. If you wanted to be sneaky and pick lock's, you'd have to sacrifice power as a wizard to do that. Would you still want to?
Your list of skills you're "good at" is
*Concentration (keeps you from screwing up spells in battle),
*Craft (making items, different "Craft: "whatever" skills for different things, like Craft: Weaponsmithing )
*Decipher Script (Lets you read obscure languages)
*Knowledge: (Same as Craft but with knowledge, Knowledge: Arcane gives you knowledge on magic, Knowledge: Religion for religion, Knowledge: Nature, etc.)
*Profession (Like Craft and Knowledge, but you know a trade to make money with. If you get Craft: Weaponsmith, you could take Profession: Blacksmith and use the two to work and make money in a town if need be.)
*Spellcraft (Skill allows you to know what kind of spells are being cast around you by looking at who is casting them, is important for countering spells, gives bonuses to saving against harmful spells, and is imporatant for making new spells)
Also, if you join that Order of High sorcery, you have to sacrifice three "schools of magic" to specialize in the thing you choose to, in your case Necromancy. You could not join and be a sorcerer if you wanted too, just figured I'd let you choose. Sorcerer's have a limited amount of spells they can know, not like wizard's, don't have to memorize any spells, and you wouldn't have to be Lawful like if you joined the Black Robes and follow their rules. There's benefits with the specialization though, order secret's and what not.