Some of this depends on what equipment you have.
If you only have a computer and a tape player, here is what you need to do...
Somewhere on your tape player you need to have a 'line out'. There will probably be a left line and a right line.
You will take the line out from the tape player and connect that to the 'line in' on your computer. Looking at the audio settings on your computer, make sure the 'line in' device is selected as your source for recording. Then, you will need to arrange one of your programs to record while playing the tape. After you have all the tracks recorded, you will need the right software to burn those onto CD. I am assuming you already have that, but if you need anymore help, just write another message.
Some things to keep in mind...
Most computers ONLY have a mono line-in jack. This means that your recording into the computer is not going to be in stereo. The best thing you can do is to get a 'Y' adapter for you cable, put the left and right output from the tape on the 2 ends, and put the single part of the 'y' cable into the computer.
Another thing is that the outputs from your tape player are probably using RCA style cables. You will probably need an adapter since the line in for the computer usually only uses a 1/8" jack.
When you record the tracks from the cassette, you will probably want to record each track, save the recording and record each track separately, or else your wave files will be huge and will be hard to deal with.
I am sure others will add to this, but hope this gets you going for now.
There is a way to record stereo into your computer, but it will probably require you to get a new soundcard.
Let me know if you need more help
Micro