Borders has a Corporate and Educational Sales Program- if you own a small business you can pick up an application at any Borders store. (usually near the info desk) Send it in and in a few weeks you'll get cards for yourself and any employees you designate. It gives a discount (iirc it's 20%) on books. No discount on magazines or coffee. They have two categories, "discount only membership" and another which I believe is a revolving credit account.

I don't know what the educational half of the program is, perhaps teachers can also get a similar discount.