If you're not familiar with Rainbow Resource, it is a family owned business that sells homeschool curriculum, books and supplies at discounted prices. It also offers free shipping on orders over $150.
The Rainbow Resource catalog is the size of a phone book, and is organized by age and subject. It contains detailed reviews of each product, and is a great source of information about homeschooling resources.
I love it even more than those J.C. Penney Christmas catalogs I used to drool over as a child! You can request a free catalog here.