If you want to donate money to this site, here's the place to do so.
Currently (as of 01/2014) this site is now on paid hosting, with a proper paid domain name. I think I learned my lesson about the reliability of free hosting. I anticipate the trickle of money I get from book sales to more or less cover hosting expenses (it's still pretty cheap paid hosting), but as always, donations are appreciated. Please note that you shouldn't try to donate by buying more books (unless you just want more books; if you do, go ahead): I only receive a few cents from each sale. The vast majority of that money goes to paying for printing costs and the publisher's fees.
Donations occur through PayPal, which will accept major credit cards if you don't have an account. I never see your credit card information, and the transaction does not occur through this site.
Thanks in advance!