http://www.goldwave.com
http://www.ntrack.com
The guitar is an unpowered instrument, so you won't hear much of anything if you go direct to the computer without an amp. Hook up your guitar up as usual to your amp, then run a cable from the mic out to the line-in on your soundcard. You'll probably need an adapter to go from 1/4 to 1/8, unless you have a Live drive or something along those lines.