Books and Supplies
This is a non-profit book dispository in Glen Ellyn. They have some wonderful textbooks, workbooks, reference, and reading books to choose from depending on when you go. All books are free, but according to rules, may not be sold.
They have the largest parent/teacher shelf I've seen at any library, as well as hundreds of reproducible workbooks and unit studies (including many of my favorite, Teacher Created Materials). Also many free education dvds and videos.
This library has a resource center especially for homeschoolers. You can check out microscopes, Saxon Math, and so many other useful items. A great way to preview something before buying. Even though it's about an hour from Chicago, it's well worth visiting.