I have just finished ripping these
my CD collection, into Apple lossless audio files. Now I will never need to rip my music again because unlike MP3 or AAC files there is no compression, so converting from Apple lossless to another future lossless format means no audio quality is lost.
Converting to Apple lossless has blown out my music folder from around 120 gb to just under 160 gb
As you can see I am a huge fan of Podcasts and have a few audiobooks as well.
Itunes University is pretty good as there is a lot of good free stuff to watch and listen too.