Signing up with Donors.com is a very easy process. If you are visiting Donors.com from a desktop or a laptop on the top right corner you will see a menu item / button named "SIGN UP" click on that button to start your registration process with Donors.com.
A click on the "SIGN UP" link will open the Donors.com user registration form. Nothing to worry about its very simple and can event do a quick signup using your social accounts.