Bibliomancy is my preferred method of divination. Most people have heard about it, even if they don't know it by that name. Have you just opened a book and let the pages fall where they may, looking to see which passage caught your eye? That is the beginning of bibliomancy. Many people I know who are Christians do this; they hold open their bible and let the pages fall, and put their finger on a passage. It helps to have the person who wants their question answered holding the book, but when someone has been doing bibliomancy for years they can do readings for people other than themselves simply because of their practiced ability to change the energy flow from their hand.
How bibliomancy works, or at least how I have perceived it to work in my years of doing it, is that the book is responding to the vibrations of energy coming off of your hand. This is why it can work for anyone who just holds open a book. Those who work with energy on a regular basis can also do it a different way, by holding the book closed and hovering your hand over it. Your fingers will be drawn to the place the book should part. They next part of bibliomancy comes in choosing the proper passage. Generally, this will be the first one that your eyes are drawn to when you look at the page. If you can't make sense of the reading, don't try again with the same book. You should never use the same book twice in the same reading. I once had three different books give me the same answer when doing a reading for a friend. It is situations like that which tell you that this is a working method of divination. Twice can be coincidence, but I don't think three times is.
Which books should you use? I know some people that refuse to use fiction. I know some that use only religious books. I personally use whichever book feels right. I strongly feel that there is value in every written word, be it fiction or not. My favorite books to use for bibliomancy are classics; simply because many people know of them and can identify with them. The Hobbit and the Lord of the Rings series, books by Charles Dickens. The writings of Virgil and Homer. Regardless of what you chose, be sure that the book calls to you. If it feels like the right one, then it is. If you don't feel a thing, then move on to the next one - you won't get a good reading out of a book that you don't connect with.
Bibliomancy is a good way to get advice about things, because everyone connects with the written word. I actually offer bibliomancy readings on Fiverr.com, but I won't link it here unless someone asks because I don't want to be spammy! If anyone needs some help trying it themselves, feel free to give me a shout.