Actually, I suppose it's not so surprising, but I did not think that Books-a-Million had a whole lot of materials suitable for homeschoolers, but they do.
Of course I know they have books. I mean, I am not that slow. LOL
What I mean is that they have a whole section for books specifically for homeschoolers - workbooks, worktexts, and also books about different homeschooling philosophies.
One series I like for "supplemental" work is the Spectrum series of workbooks from McGraw-Hill. They have different books for grade levels and subjects: Reading, writing, math, etc. Nice stuff for extra practice and for a little variety, you know? :o)