[livedead13]

Assuming you have both pieces hooked up to a reciever, just take the line output from your reciever and connect that to the line input of your soundcard.
Then you would need a wav recording program such as Wavelab or something. Open the program, go to the audio setting, adjust volume levels to where it is not clipping, and record. If your computer is slow, record each song individually. It will help speed up editing when working with a smaller file. If you have a solid cpu, I would just record the whole album or cassette to one file, so you don't have to sit there and mess around with it all day. Once the file is recorded, you can process and edit to your liking.