Assuming you are using a mini-DV camera, then all you would need to import video is a firewire port. If you PC does not have one, they can be purchased on a PCI card for around $30 - $35. You would then use the "Import Video" option from your editing software.
Depending on your budget, you will spend either around $100 (decent) or $500 (advanced) for editing software. If you are just starting out and want to get some good practice, the $100 software packages are just fine. I have used Pinnacle Studio (which is okay), but I have switched to Sony Vegas Movie Studio and I like that much better. It is a great value.
You will need a modest primary [C:] hard drive -- something just large enough to load the operating system, your program files, and your cache files. Then, you need to get the biggest hard drive you can possibly afford and install it as the secondary / slave drive (200 GB - 250 GB). Do NOT try to import video to your C: drive. Always import to a secondary drive.
www.microcenter.com usually has good deals on big hard drives.
Processor does not have to be super fast. I have a P4 1.7 Ghz and it works fine for me. Of course, faster is always better... I WOULD recommend going for at least 1GB of RAM, and again...more is always better.
That should do it.
There have been a few posts already about this -- so you might want to search for those to get additional information.
John