You are taken to Paypal (my payment processor, one of the - if not the - most trusted name in online payment processing) where you follow the instructions to set up either monthly donations (that are automatically withdrawn each month from whatever funding source you input - check card, credit card, etc.) or to complete a one time donation in any amount you want.

I personally support three different online shows/show networks (The Bitterest Pill, TWIT.tv, and SQPN) with monthly donations processed through Paypal. (I wouldn't invite you to do something I wouldn't do myself!)