Re: webcasting equipment
In reverse order:
UStream is a free webcasting service that can also record whatever you broadcast and save it to your channel on their website. The free version has obnoxious ads that pop up every 15-20 minutes. For a subscription fee you can go ad free, which is worth it. Other services exist, this is the one I'm familiar with.
If you're using a webcasting service like UStream, you'll use that program to control input from the camera to the computer. For a single camera system, this will be all you'll need.
To physically get the camera output into the computer you need a video capture card. So far as I can tell these are all a crap shoot; we've had cheap ones work great and expensive ones put out complete rubbish.
Check your internet upload speed. Most internet providers only advertise download speed and normal residential connections don't have the upload bandwidth available to broadcast anything but the worst quality live video. I assume you want to broadcast live since you're not just using Youtube.
In summary: for a single camera continuous broadcast, all you'll need is a camera, computer with video capture card, and some webcasting service. I'm sure a bunch of them exist, I'm just familiar with UStream. For multiple cameras you'll need a video switcher of some type.
