Hi 06sc500,
You will need software to record and mix with. Audacity have a very good, and free, one which is simple to use. http://audacity.sourceforge.net/ to down load it. Russ also has put several tutorials to help you get to grips with it: http://www.mediafire.com/russellharding
If your guitar has an electric pick up you will need a lead to connect it to your PC and an adaptor to reduce the jack plug size.
You will need a microphone for your vocals (and guitar if it has no electrics). It is advisable to get the best you can afford as with a mic the better the quality the better the audio.
When recording it is always best to record the music first. You can record one or more tracks of guitar, pan and balance before adding the vocals, again you can add extra vocal tracks for harmonies, ooh and aahs before making a final mix and saving as an mp3 for upload.
There are several posts in this section with more detailed help on recording too. Her is one I put up a little while ago: http://www.chordie.com/forum/viewtopic.php?id=9253
That is it in brief for more help see the tutorials and ask questions here.
Roger