How to Convert Cassette Tapes to CD

I have a number of cassette tapes that I would like to convert to CDs, and then trash the cassettes. I found information on "i-Sound WMA/MP3 Sound Recorder 6.55 Professional" software which states that "you can easily convert ... cassette tapes to digital format." However, I can't find any explanation of any additional hardware that may be required (cables, converters, etc) in order to do this.

So, if anyone can give me a clue as to what is needed so that I can accomplish this task, it will be greatly appreciated.

My main concern is that the only audio input to my computer is a microphone input jack, and it would seem that the audio out from my cassette player might not be the right impedance, or may produce too strong a signal for the computer to handle.

Also, does anyone have any experience with any other software that will do the job?

Thanks in advance!