In my previous post, I mentioned that why I hate the big charity solicitations. HSUS and ASPCA don't distribute any of their funds locally. The small local "mom and pop" (usually mom) rescues usually have 100% of their donations going toward the animal-much better in my never humble opinion.
If claiming your donation on your taxes is important to you, be sure that the rescue or shelter you choose has a 501(c)3 non-profit status. Note that having non profit status is no guarantee of the quality of the rescue. There are many non-profit organizations that are a ripoff, and many stellar rescues that don't have the non profit status.
If you aren't aware of any local rescues and don't have a county shelter close by, here is a cool website. Adoptapet.com. Click on the "find a shelter" link, enter your zip code, and you'll get a list. The hard part is choosing. Aside from the links, this site has some awesome information on it.
While I'm not a huge fan of Petsmart in general, they are really stepping up to the plate with their charities program. I've seen some of what they do in action, and so far I've been impressed. Petsmart Charities
They also have collection jars at their registers, so if you're in a Petsmart, the money they collect is actually going to good things.
And don't forget the little guys when you're choosing a rescue. Small furred animals like rabbits and guinea pigs, reptiles and birds are often forgotten in the rush to help dogs and cats. A small donation to one of these rescues can help a large number of them. There's links on the Adopt A Pet page, and since I have on good authority this particular rescue is fabulous here's the link to the facebook page of My Hope's in You Small Animal Rescue.