For cassettes, he can just connect his tape player into his sound card and use Audacity to record them.
Video is a little more difficult. He'll need a video capture card to get the video into the PC. Lance mentioned a product by Ion called Video 2 PC Digital Video Converter which uses USB to capture video. Leo recommends staying away from USB for video capture because it's too slow. Using Firewire or an actual video capture card for the computer is better, but Lance has a laptop that doesn't have either of those options. It will have to be compressed heavily in order to work, but VHS isn't great quality anyway.
There's another more high-end product called the Blackmagic Design Video Recorder he could look into as well.