That worked great for subjects such as history, geography, geology, meteorology, basic physical science, and English. For geometry and algebra books, I'd look through books at the library to see which seemed the most understandable; then I bought them used from Amazon or ebay so we'd have our own copies to scribble in.
My son would occasionally take practice tests out of library editions of PSAT or SAT preparation books. This exposed him to test-taking skills, and was also a check on how well we were doing with basic algebra, geometry, and reading comprehension.
For high school courses, we've been using the University of Nebraska-Lincoln Independent Study High School. Almost every UNLISHS course can be taken online! So far we're pretty happy with it. It's a little pricey, but my son can take his preferred language, Latin, a course that's no longer offered in our public high school.
Boy, some people are awfully hard on a girl first thing in the morning.