At the end of the year I noticed I had a lot of books in my house. I mean, I could have started a library! I decided to get rid of all the books I didn't read or have read but kept around the house for some reason. I had about 5 banker boxes filled with books. I was going to take them to various used book places but they weren't accepting any new books. And some places only accepted once a month. Plus, I don't own a car so that put a damper on things! Then I read about some online places that allow you to swap books. All you do is pay for the postage, which is media mail, around $2 per book. Everytime you send a book, you get one credit. Then you can get a book. That's how I got "The Budget Fashionista"! I have gotten rid of over 200 books! Read them and repost them!
Plus, since I'm a teacher, it's great for my classroom library. This past year I had a Harry Potter after-school club and "bought" all of my students the first book in the series. For stay-at-home moms, you can get rid of some of your childrens' books and get "new" ones. Some of the sites accept highlighted books while others do not. Please read the conditions. I know this will cost money to do at first but post only 10 books at first. I made the mistake of posting all of my books and had to make daily trips to the post office for about a week!
http://www.paperbackswap.com (books must be in somewhat good condition, no highlighting!)
http://www.titletrader.com (any condition accepted, accepts magazines too!)
http://www.frugalreader.com (any condition accepted)