Celtic Heroes

While my mage is only 34 at the moment, I am wondering if there are spell books given as quest rewards along the main line quests, or if I need to purchase the spell books that are available? If there are, would anyone know which books are given for which quest? And/or if there are quests off the mainline that reward a spell book that I should be looking for. Granted, I am too low to probably get to those quests, but I want to have the knowledge prior to getting to the proper level to run the quest.

There are quests that require you to collect pages, covers, and bindings. (Blue cover and bindings for incinerate and red for freeze)
Incinerate is a damage over time fire spell and freeze makes the enemy "freeze" until someone attacks them again or a few seconds. All other mage skills drop from otherworld bosses. There are sacrifice (a skill that gives up health to obtain energy), lots of lures that reduce enemy resistance to slash/pierce/magic damage, and firestorm (an area of effect attack like firebolt that is currently broken as fire lure does not effect it) You should be able to pick up otherworld skill books for 3-6k