Do you have a mac or a pc? If you have a mac, its perfectly fine (and incredibly easy) to do what pimento does. In fact i recommend it for its simplicity. If you have a pc, it's likely you could do something similar using a 1/4" to 1/8" adapter and running it into your line in port (assuming you have one, most pc's do) but then you'll need a DAW (Digital audio workstation) program or other recording application. One i've heard a lot of talk about is sony's "Acid" program. Acid Xpress is available for free download on this website: http://www.acidplanet.com/downloads/xpress/
hope that helps and write back if you have any questions!
(also if any pc users out there have a better suggestion for the program, please post it, acid was just the first thing that came to mind)