I think it's important to try and donate when you can to whatever worthwhile charity you like. It doesn't have to be money, many charities need things like stuff we have around the house that we don't need or just someone to give some time. What's important is that you do something.
I figure that if I've got the extra money to go around doing 100 random things, then I should be able to spend some of that on charities. There are all sorts of great organizations out there that you could help, here's two that I like:
1) The Children's Cancer Center in Tampa, FL - This one hits close to home for us and they do a ton of really great things for kids who have cancer and for the families of those kids. They have fundraisers all over the place or you could sponsor a family for the holidays or you could just buy some Christmas cards.
2) Daystar Life Center in St. Petersburg, FL - I won't hold it against them that they are a religious organization, because they do some good work in my immediate area. I hadn't really spent much time thinking about homelessness when I lived in the suburbs outside of doing my best to stay away from them, but now that I live in an urban area I see how big of a problem it is and I decided that I need to try and do more. I gotta think more about what I can do in 2013, but donating to these guys was a start.