Curriculum Cottage is really wonderful. I'm a homeschooling parent and I really love the selection of workbooks and resources. Everything here is geared toward homeschoolers, so you can buy single pages of items rather than entire packets. When you are working with workbooks in a series, they are the most likely local source for finding the workbook you need. Additionally, you can peruse expensive curriculum materials before buying.
I do not homeschool for religious reasons and this is definitely a store that assumes Christianity in its customers. I've never felt preached at as a customer, but someone of another faith might feel uncomfortable with the assumptions. The only other downside is the limited hours, but needing to plan ahead probably keeps me from impulse buying way too much stuff!