Get the Biggest Benefit for Your Gift
Lastly—and this is the trickiest thing to gauge overall—try to give to an organization that actually gets the results you seek. You can get a sense of effectiveness through the websites listed above as well as through the Better Business Bureau, all of which rate charities based on factors such as how they spend their budgets, how much they spend to raise funds and how transparent their finances are.
If you still feel you need more information to make a good decision, call the organization itself to find out what they are accomplishing in your area of interest, or if they have special holiday fundraising programs to which you can donate. Doing so will also help you feel sure that their work aligns with your own interests.