Here is a link for help with MP3s -
http://mp3.about.com/cs/mp3basics/
I use MusicMatch, and have purchased the premiere version.
You can easily convert files from one format to another using this software.
Go to Find, Convert and you will have 2 'boxes'.
Right box you navigate to the folder you have your music collection in and select indivdual songs. Right box you navigate to the folder you want the converted songs dropped into.
You can select what format you want to use (MP3) and the bitrate (128 for the 7135, 160 or 192 for players or computer or CD burning for playback elsewhere) You can also choose Audio to make straight music CDs for playback in home CD players or cars.
To 'rip' music, you go to Options, Settings and click on the Recorder Tab. You can set the file type, bitrate and destination drive - then insert your Audio CD into the computer and click the red Record button - it will take your songs and put them into the directory you indicated in Settings.
Music Match also has a great website with FAQ pages to help novice learners.