the issue w/ itunes, imo, isn't re: DRM, it's more about the BS of only being able to play them on permitted systems. every MP3 i've ripped from MY collection is copyright free, cuz i don't want to mess w/ whether or not i can play it on my iBook, my windows desktop, my MP3 player, a family member's system when i go to visit, etc. if licenses ever become truly portable i'll think about it. until then, it's my music and i'll listen to it on any device i see fit.
Taelvin, are u on a PC? if so i tend to use nero to burn a disc image of the songs i've purchased. u can use nero's virtual disc utility, to mount the image, tho i usually use daemon tools to do it. then u can use nero, or whatever ripping software u see fit, to encode the tracks to MP3s at the bitrate of your choosing. but, as u may be looking to make a hard copy of your downloaded music actually burning a CD (then ripping) would work too. for me, the vast majority of my collection is made up of good old fashioned store bought studio CDs, w/ a handful of DRM stuff that i've burnt to add to my collection in the car, cuz in the house, why would anyone actually use a CD player?
w/ re: to your system being a Mac, i'm not sure about the process. i'm guessing it involves software like toast and the creation of a virtual disc, but i haven't had a need to do anything of the sort on my iBook. i.e.-since my desktop has the faster CD-ROM/R/RW i usually just do my stuff there and drop my tunes onto my iBook over the network.