To determine how much your book is worth, you will want to take it to a used book store. Most books are only worth a few dollars. However, if you have a historically significant book, you will want to take that to a curator or a pawn shop as they might offer you a lot more.
The value of a book depends on a number of factors:title, author, year of publication, condition, rarity etc. You can visit the local book store to find out these information about the book and then get a price estimation online.