The main thing that you need is a way to get the VHS video into a digital format and onto your computer.  You can do this in a number of ways depending on the equipment you have or plan to buy.

The cheapest thing to buy is a video-in card for your computer.  This will allow you to plug cables from your VCR or camcorder into your computer.  If you own a digitial video camera, you can probably plug your VCR into your digital video camera and then plug that into your computer.

You will also need software, but this might come with the video card.  If you use a Mac, it comes with iMovie which can import from your digital video camera and let you edit the movie.  Adobe makes a product (the name escapes me at the moment) that you can buy for the PC (and might come bundled with the video-in card you buy).

Once you have the video digitized in a format that PowerPoint understands (e.g., AVI), you can insert it into PowerPoint by going to the Insert menu, choosing Movies and Sounds, and Movie from File.

This is a quick overview.  Let us know what details you need filled in.

--David

David M. Marcovitz
Author of _Powerful PowerPoint for Educators_
http://www.loyola.edu/education/PowerfulPowerPoint/