If you are purchasing on behalf of a business, I highly suggest using Amazon Business Solutions (
http://www.amazon.com/b/ref=nav_swm_b2b_sln?ie=UTF8&node=11306076011&pf_rd_p=2073948862&pf_rd_s=nav-sitewide-msg&pf_rd_t=4201&pf_rd_i=b2b-nav&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0XVHWPW88BMVDYDRGREW)
We set up as a business and it's great. It's free. I uploaded our tax exempt certificate. You get FREE Two-Day shipping and business pricing on supplies like paper, pens, ink/toner, etc. I've set it up so that I can have multiple employees (my Head of Youth Services, my manager who purchases African-American fiction, and even my IT Specialist) can order using a PO system that I (and a designee) can approve before it's ordered. We're even using their 55-day Pay-in-Full Line of Credit (as of last week). It's great to get all that off the credit card.
And, honestly, the best part is that when I call about a lost order or a return, I get a dedicated team of business for business account managers. So much better than before.
Good luck!