You can click and drag them into iTunes. If that doesn’t work, burn them onto a cd, then transfer them to iTunes.
Well, if they are in the WMA format, you will need a codec for media player to convert them to MP3 (MP3 works fine with ipods.) I found mine via a link at windows websight. I believe it cost about 9 dollars. It works very well. If you have a small batch of files to convert though, you can burn them to a cd as audio files with media player, then rip them to apples format with itunes. Ofcourse you’ll sacrafice a blank disk to do this.