I'm just wrapping up final mixes for my band's self-produced EP. We're going to distribute digitally via iTunes, Bandcamp, etc, and also get a few CDs printed.

Can someone point me to some sort of documentation about how much headroom I should leave for each format? Apple suggests peaking at -1dB (http://images.apple.com/itunes/maste...for_itunes.pdf), and I know I've seen the number -3dB thrown around a bit. I won't be doing much actual mastering, but I do want to make an intelligent choice about how to set my final limiter.