Wal-Mart is everywhere and is a reliable, inexpensive place to find supplies like rubbermaids, thermometers, and human heat pads. However, I personally have some ethical reservations about supporting a company that has ~75% of its full-time employees eligible for food stamps, so I buy elsewhere when I can find it and the price isn't ridiculous. As far as buying supplies online, bigappleherp.com will be able to provide just about anything you might want.