Recommendations:

Use VP Capture to capture and edit your movies

You can also use VP Capture to edit QuickTime movies from other sources

QuickTime Pro offers many additional editing options for only $30

Check out what equipment might already be available to you

Digital Video and IEEE-1394 are best for video capture

Look for IEEE-1394 (FireWire, i.LINK) in your next computer

A USB webcam can get you started

Logger Pro 3.4 from Vernier now offers basic video-based motion analysis and video capture at a budget price if you do not need all the features offered by VideoPoint and VP Capture

Have fun!

Links:

Pat Cooney's Home Page
VideoPoint
LivePhoto Physics
Vernier's Guide to Video and Logger Pro
Apple QuickTime
QuickTime Pro book
and type "camcorder review" in Google for many more links