This is entirely up to you. The current amount of money donated so far for every project is indicated in the project list (right-most column) so that you can see anytime precisely which projects you can sponsor and how much you can donate.

You can choose to donate as much as you want, there is no minimum amount of money required because we believe that every little contribution can make the difference. You can also donate several times for the same project as long as some money is missing, and of course you can also sponsor different projects appearing on the list. In other words, you are entirely free to distribute your donation as you want.