Divine Intervention Book

Aesrela Everild (AE)
Pre-reqs: none
Description: Holy fire bolts rain down on the enemy, as long as you're outdoors.
Comments: Non-targetted spell that teaches a *little* bit of TM. Can be a decent spell if you train your Targetted Magic. Your TM skill has a noticeable effect here. I personally use it just for show, or to get rid of annoyances while hunting. I would not consider this a training spell. While it can be useful at times, I don't recommend this spell until much later when your TM will make this spell useful for you. There are easier and faster ways to kill low level critters when you're young.
Usage: I tend to backfire if I don't wait till almost the full prep. I use between 5-10 mana preps when attacking creatures.

Confound Enemies (COE)
Pre-reqs: Divine Radiance, Protection From Evil
Description: When cast, the enemy will have a harder time trying to hit you with a Targetted Magic attack.
Comments: A held mana spell. Currently, it does not seem to have a satisfactory use when hunting critters. There aren't very many critters in the game that employ Targetted Magic spells. Thus, this spell doesn't really come in handy much. I really wouldn't recommend this spell unless you want another Primary Magic trainer.

Hand of Tenemlor (HOT)
Pre-reqs: Harm Evil
Description: Targetted Magic attack which comes at the cost of a severely scarred left hand.
Comments: Quite a powerful spell, but with a significant cost. If you intend to use this spell, have cebi root and jadice pollen handy. I don't recommend this spell for young clerics, since it costs a lot to cast this spell.
Usage: Takes quite a bit of mana to cast. Min prep is 16. Urg. (Work your power perception!)

Curse of Zachriedek (COZ)
Pre-reqs: Kertigen's Will
Comments: This spell places a curse on the enemy's weapon, shield and worn armor. While similar to Malediction, this spell affects the items, rather than the skill. This seems like a pretty good spell.
Usage: It weakens the protection of your opponent's armor and shield, while reducing the damage your opponent's weapon will cause. This means you will be able hit them harder, while they cause reduced injuries when they hit you. When cast, the cursed items are stuck on your opponent, and can only be removed by uncurse. The protection and damage curse however cannot be removed at all, and your opponent will have to wait for the duration of the curse to fade.

Osrel Meraud (OM)
Pre-reqs: Bless, 15th circle
Comments: Basically, it allows you to use a held mana spell, while still being able to cast other spells, without losing that held mana spell. It's very useful if you're a fan of held mana spells, but find yourself hindered because you also tend to cast while in combat. It seems to last quite awhile. You can have 1 or more held mana spells on the orb, depending on your Magical Devices skill. I like this spell a lot right now, because I can use Shield Of Light and still cast other spells while in combat.
Usage: You need a favor orb from Meraud, Firulf or Kerenhappuch. No need to sacrifice anything. Cast the spell on the orb. You can recharge or add more mana to the orb by repeating the spell cast. If you use cambrinth orbs, cast on the cerulean orb so that there's no mix-up. You should know at least one of these spells before you decide to get OM: Centering, Shield of Light, Confound Enemies or Mass Rejuvenation. You should like and want to use at least one of these spells often, otherwise it's not worth getting OM.

Murrula's Flames (MF)
Pre-reqs: At least 50th. Other than that, not sure.
Description: Basically, it's a self-raising spell.
Comments: It has an awesome quest (kudos to the GMs)! The spell itself doesn't really appeal to me, because the benefits don't outweigh the cost for me. However, if you're a cleric with a tendency to hunt in isolated areas, where obtaining aid is almost impossible, this spell could be for you.
Usage: This spell is stackable. When you die and get self-resurrected, you lose one favor, all your field experience is gone, and your wounds still stay with you. Any bleeders will be temporarily stopped as Hodierna's Commune is automatically activated. If you have critical wounds (i.e. no head), you will be healed enough to be resurrectable. When you die, critters will normally wander off and sometimes they wander back in again. This hasn't changed with the spell, so there is still a risk that the creatures will attack again. So be prepared to leave fast. Also, once this spell is used once, you won't be able to cast it again till much later.

Glythtide's Gift (Scroll Only)
Pre-reqs: None
Description: You become a walking bartender.
Comments: This is a fun spell. You get plenty of drinks.