how can I record off my desktop (IBM)
 

I get some charts for church and a link to the songs on Youtube.I would like to record the audio and put our whole set list together on iTunes.Then I can take it with me. I have a earphone jack on the front of my tower,would I use this and split it left and right? Of course youtube is mono I guess

There are a variety of "youtube downloaders" out there, some of which will save just the audio. These are of contested legality, so do your own research...

Another option is to set up your audio in the PC to record "what you hear." Not all soundcard drivers include that functionality.