only necessary if you use mp3 rather than aac (which has far better audio quality at lower bitrates than does mp3).
I didn't know that. Everything I have is in MP3 format because most of the stuff I ripped from CD was done before I got my Ipod. I used WMP and it does not rip using AAC. Doubt I'll go back and change anything now though. I have years of ripped CDs on my computer in MP3 format.
i dont understand podcasts... anyone know? ...like do they go on your ipod or are they just in itunes?
Think of podcasts as downloadable radio shows. You can subscribe to them in iTunes to automatically download the latest episode, although there's nothing stopping you from putting them on your iPod or any other portable music player, as it's just an MP3 file that they distribute.