There are many options and ways to capture video into a PC these days. But with the speed of current PCs there isn't a need for an actual capture card as such for the processing any more (unless you were working with HD), although it does depend on the PC setup and if you have other hardware.
Many newer graphics cards have a video in, so it is worth checking that first. Failing that, if your PC has a firewire port, and you own a camcorder with a firewire port then you might be able to use that.
Most digital camcorders these days provide an analogue-to-digital passthrough capability, allowing you to hook up an s-video source to them and to then feed this live via the firewire port (the camcorder performing an analogue to digital conversion on the fly which is often much better quality than standalone analogue video capture cards, and the reason I use it). Read more about this at
http://www.videohelp.com/dvanalog
The big advantage of capturing video via the camcorder method is that the resulting video files with be in DV AVI format at about 3.3 MBps, which is a great format to work with when editing video as it is much smaller than uncompressed formats like RAW AVI, and is not as compressed as formats like MPEG2 which were not designed for editing.
Failing that, the next cheapest option is to get a USB capture card. It just plugs into a spare USB2 port on your PC and lets you capture any analogue video source directly to HDD.
The best consumer video editing software for this is Adobe Premiere Elements, but the cheaper Pinnacle Studio is also quite good. There are also completely free video capture packages, including
VirtualDub which I recommend. There are loads of tutorials on how to use VirtualDub found on the Doom9 and videohelp sites. Such as
http://www.doom9.org/index.html?/capture/start.html
Also have a look at
http://www.videohelp.com/capturecards to look at the available video capture cards on the market. You can break the search results down into the type of card you are looking for, such as AGP, PCI-E, USB etc, and also the features you want on it.
A USB2 capture card can be as inexpensive as $50.
