I would suggest using reaper....REAPER is a fully featured multitrack audio and MIDI recording, editing, processing, mixing, and mastering environment...and can be evaluated with full functionality...
http://www.reaper.fm/
Computer specs for reaper
Recommended system: Multiple processors, Windows 2000/XP/Vista with 1GB RAM, >1GB free disk space, 1280x1024 in 16.7M colors, ASIO sound drivers
Minimum system: 500mhz processor, Windows 98/ME/2000/XP/Vista/WINE with 128MB RAM, 10MB free disk space, 800x600 in 256 colors or higher, Windows compatible sound hardware
AUDIO
get yourself a 1/4female-1/8 male adapter to plug from your instrument to your soundcard (mic input or line in input) and you are good to go..
there are audio interfaces out there that you can use to record instead of going into you audio card on your puter....some are USB interfaces and some are Firewire interfaces....From what ive read...the firewire is the way to go...but you will need a firewire card installed into a pci slot on your puter if you dont already have one..
MEMORY and Processor
The more you have the better...when i started i used a 1.2 ghz laptop with 128mb ram and 30 gig hardrive on Windows XP....about 4 tracks was all i ever used then but i wasnt using alot of effects...and it held up fine....
Learning
Play around with it....getting started sections are a good way to get the concept of how the software is setup...