Here you go: motioninjoy.com
That's what I use to get my DS3 and SIXAXIS controllers working on my PC.
Follow the instructions carefully. I haven't used it in a while but the last version I installed didn't just require installing the file there. After that it requires individually installing the bluetooth and USB drivers. It's been a while so I don't remember, just follow all the instructions and you should be fine. Keep in mind in Windows Vista or 7 you'll need to disable driver signature enforcement. At startup press F8 and select disable driver signature enforcement. I'm not sure how to disable it permanently.