How to transfer language study material on cassette tape into a computer

I have a shiny new XPS 630i running on Vista and a  Dimension 8300 running on Windows XP.    I want to transfer some language study material on cassette  tape into one of the computers so that I can burn it onto a CD for use in my car or load it into my iPod but I don't know how to connect the cassette player to the computer.  

Can I just connect the earplug out point from the casette player to the microphone in socket on the computer or is that too easy?

I understand that some sort of transfer software is required - Gold Wave was mentioned to me.   Is there any free software around?  How do I use it?

Two-thirds of Queensland (in Australia) where I live is currently under flood, unlike Victoria where the bush fires are raging, so I need something to keep me occupied.

Any help gratefully received.