This isn't much of a guide, but I found something out that's rather nice today.

If you pick up items, you may eventually find an item looking like this. Don't throw it away though, it's quite useful.

Now once you have it in your inventory, hover over it with your house and you'll see something like this.

The top blue number (25) means the required level to use this book. The bottom left number (1100) is the amount of money the quest gives. The middle number (1800) is the amount of exp it gives, and the right number (410) is the amount of SP given by the quest.

Now if you are at least the required level, you just have to double click on the book and have one quest slot open, and it'll appear in your quest journal. Don't fear though, so far from all the quests I have done from books, it's just find the NPC and you get the reward. It even has the arrow pointing and the coordinates of where the NPC is. The rewards are low from these books, but it's an easy way to get some quick exp. If you get more than one of the books that are the same kind, they are repeatable.