Before storing your books, you'll need to make sure they are repaired, prepared and ready to go. Be sure to examine your books for things like broken spines or loose pages. Tape them up securely so the storage doesn't cause more damage. Look for any books that might be damp and could cause mildew, and check for spots or stains. This also is a good time to go through some of your books and donate some of the ones you don't need anymore to the Salvation Army or another deserving charity, before you proceed with storing the rest of the books.
If you want to store your books out of the way, but still want them to be on display, you can hang them on shelves in your rafters for an interesting statement. Using your rafters as dividers, you can purchase some wood from the hardware store and nail it under the rafters for the bottoms of the shelving. If your books are particularly heavy, you may want to use brackets as well to make the shelves more secure. Use a rolling ladder and place all of your books up in the rafters. Organize them by author, so when you need a book, you can roll the ladder over to the right rafter and pull it down.
If you don't have a lot of space in your home and are trying to utilize every inch, you can use your closet rods as a handy and innovative place to store your books. By purchasing the "Salkim" metal hangers developed by design house Unal & Boler, you can use your closet as a book hanger, rather than for clothes. The metal hangers can hold six or seven books, and can hang one on another, utilizing all of your extra space, while still keeping your books organized while in storage. And, if you love the look, hang them in your home where they can be viewed. As a twist on usual storage, consider storing the books by color to make a statement in your decor.