We recently pulled my youngest daughter out from public school to homeschool again. One of the things she enjoyed that was also helping her to keep track of the books she was reading and keep her motivated to read more everyday was the Accelerated Reader program by Renaissance. The program helped her to pick out books and also has a 5 question quiz they could take to earn points that her teacher would reward her for.
Unfortunately the Renaissance company does not sell to homeschoolers and her school would not let her keep the account. So I was determined to find something similar that was available to homeschoolers.
Book Adventure by Sylvan is very similar and it's FREE! The other great thing about it is the kids earn points when they score a certain percentage on their quizes and use them in an online store to "buy" things like temporary tatoos, chocolate and other small prizes. There are also contests that you can join or create for your homeschooler.
Additionally, you can create book lists to print out and take with you to the library. This is helpful because not every book in the library will be in the Book Adventure system.
To check out Book Adventure go to bookadventure.com.