It mostly depends on the camera.

What i usually do when buying something i know little about, is i always try to by the 'mid range' priced one. It is a trick that so far in life, has never let me down. Naturally if i can afford a bit better than mid range, i will do so, but i never buy the 'most' expensive unless i really know the reasons why.

As for software, CNET downloads is very good.

Well i have never done that, but presumably you would use your VGA or HDMI output to the camera? HDMI preferably because VGA doesn't carry audio signal (not that you cannot use VGA with a separate audio output).

I suppose their would be programs for capturing video on the computer, but i would bet they would be sun-of-a-bitch hard to use and then you have to deal with all the different formats and programs that are not compatible,,,, aaarrrrgg, just horrible, stick with the camera!