What's a bookworm to do?

I am a huge bookworm and can never throw out a book.  I even have a blog about books! It seems like a sin to do that or something! I have a couple bookcases full of books and then more in storage in box after box.  I'm not sure why I don't just sell textbooks...it's not like I'm going to use my textbooks from college and by the time my kids are in college, they'll be totally obsolete.

Do you know of anybody who makes money from doing this regularly?  I know of one person but I've not heard of anybody else yet doing this successfully.  It's a thought since I have so many books and can probably get my hands on many more. With six kids, we can definitely use the money!