Magic system explanation please? Not quite sure how to do a Mage if there isn't anything explaining it.
Sorry, I got distracted by the others! Here's how being a mage works:
In order to cast a spell, you must first find/buy a scroll with a spell on it, and have at least one rank in Craft: Literature (Runes). Concentration and Attunement also both help your success rate. You then read the spell off the scroll, and if you succeed in all the rolls, you cast it. Casting degrades your scroll so it loses power and is eventually destroyed. This can be prevented with the use of Attunement knacks. The Attunement knack
Memorizer (which requires Attunement IV and Cleverness II) allows you to memorize a spell off a scroll and cast it at will with only the Attunement check. Learning it counts as a use on the scroll. In order to memorize more than one spell at a time (especially since memorizing them takes a lot of time so it can't be done on the fly), you have to get the Attunement knack
Spellslinger, which lets you learn additional spells at the cost of 1 maximum HP per spell beyond the first (so knowing 3 spells at 20 max HP gives you an effective max HP of 18). The other knacks
Latent Barrier and
Enchanter just let you do more things with your spells.
Mages are by far the most complicated build because the game is low fantasy, so magic is very rare. Making a mage represents a significant time investment and you will not be able to do it right when you start the game (you must be at least level 7 to have the bare minimum of required skills to cast a spell from memory), but you can definitely start down that path.