. . . and here's how to do it for free (except possibly for the cost of a cheap lead):
Assuming that you've already got a record deck, you need to choose a suitable output. Ideally, if you're using 'hi-fi separates' the best source would be the phono outputs from the record deck. If you've only got a deck with a built-in amplifier, you might have to use the headphone socket. (If so, keep the volume set low).
Now find the relevant audio input on the back of your PC. This will probably be a 3.5mm jack socket. Head for your local branch of Maplin Electronics and purchase a lead to connect output to input.
Now all you need is some suitable (free) software. The most popular program for recording (and editing) audio is probably Audacity:
http://audacity.sourceforge.net/
Chris