My favorite webcam for planetary imaging is the Philips ToUCamPro 740K!
Here are a few links where I found these webcams for sale at the time of creating this webpage:
This site has now been updated and is selling the Philips ToUCamPro II 780K. I have no experience with using this newer webcam.
You will need to remove the lens from the webcam and replace it with an adapter that will allow you to slide the webcam into any 1.25" diagonal or adapter. The adapters are available at the locations referenced above and also directly from Steve Mogg.
A really nice freeware software package from capturing your video is K3CCDTools.
I also use Registax to
perform wavelet processing after the video frames have been stacked.
Tutorial for processing webcam planetary images:
If you liked the older tutorial format it's still available here: Old Registax Tutorial