ToME WikiNo spoilers here, please. NO SPOILERS HERE!
Sorcerors are to magic what Unbelievers are to melee. They are the all-around best magic users, being able to cast spells from any school using only a single skill. On the downside, they are the worst fighters. They cannot comfortably use any weapon but a Mage Staff, and even with a Mage Staff, they will be unable to achieve anything remotely resembling battle effectiveness.
The energies used for learning Sorcery sap the life force of a Sorcerer, penalising them with the loss of a percentage of their hit points equal to their Sorcery skill score and penalising their combat ability even more strongly.
For more information on magic, schools and spell effects, read more about Magic.
Starting stat modifiers, starting Skills, innate abilities and starting equipment: Please see the in-game help.