Yes, might be better to ask in the more appropriate forum, but for now I can help some..
As of 10.4.9, OS X has built in support for USB webcams. The catch is, they must be UVC compliant (USB Video Class). So look for this on the box/specs.. However, even cheap cams like the USB Xbox 360 vision cam are UVC compliant. And sure enough, this works on macs right out of the box with nothing to install. But there is a catch there too.. I dont believe this cam has a mic (Someone correct me if I am wrong).
Besides this, there are quite a few UVC spec cams available, so take a browse around. They dont have to be UVC spec of course, but then you'd need to be certain the cam is supplied with Mac drivers. Which some are, but not lots by any means. So the UVC thing is quite helpful to us Mac users.