There are collections of unsigned bands, fan homages to individual low-profile acts, and hot singles for free download at big shopping sites. Individuals post songs on newsgroups. There are search engines solely for MP3 files, and there are the decentralized music libraries of Gnutella, Napster, and their evolving progeny, though legal challenges threaten these. Spend a little time browsing some of the larger MP3 sites or use search engines, and you'll come across songs and links aplenty. Downloading from the Internet depends primarily on connection speed.
Broadband access allows for whip-fast downloads.
You can make these directly from your CDs to a CD-R disc, mix and match music and MP3 files, or make a collection of your favorite playlists. CD-R disks hold 650MB of music, or several hours of music in MP3 format. However, since a disc with MP3 files can be played only on a computer or on special MP3 players such as netDrives Brujo, you'll want to make audio-format CDs, which will hold about 74 minutes of music. Once you've written to the disc, the data is there permanently. You might get pops and clicks in your recordings, or translations that end the songs early, or a recording that fails in the middle and kills your entire effort.