Probably not a good idea to record that way using the mic input, at least not without a pre-amp.
Recording while using the computers' line-in would be a better choice.
I suggest getting Goldwave to record it onto your computer, search download.com for that program. I've used it before to do just that what you're planning on using it for, did a great job for me.
One tip, make some short test recordings in the beginning, so you can adjust the volume of your recording, so its not too low, and not clipping either. Compare the volume with some professional mp3's while you're doing that.
Greetz, TK