Firstly you would need a device to capture the video onto your pc. What i/o formats does your video camera support? It will usually be S-Video or firewire. If its S-video, you'll need a TV capture card - if your mum's paying - get a geforce fx 5950 Ultra :) - if not, then you can pick a cheepy one up for around £40. If its firewire you'll need a firewire port on your puter - these can also be purchased to plug into a free PCI slot.
Once you have your video transfered onto your PC you'll need some sort of software to edit it and export the individual frames to an image file. I think the video editing software that ships with Windows XP has these capabilities, if not a quick search click here will allow you to find a freeware or shareware tool that will do this for you.