How much should I sell books for?

I was going to sell a lot of books at a yard sale with my friend, but I'm not sure how much to sell them for. I am selling everything from Harry Potter paperbacks to the Princess Diaries to Warriors to the Immortal Series to Judy Moody to Meg Cabot books to best-selling young adult book.They're all lightly used or have never read. So how much do I sell them for?