My /etc/apt/sources.list (for Debian squeeze)

My sources.list entries:

# local repo (manually downloaded debs, etc.):
deb file:/usr/local/packages ./

# The closest Debian mirror is at Dalhousie University, Halifax:
deb http://mirror.its.dal.ca/debian/ squeeze main contrib non-free
deb http://mirror.its.dal.ca/debian/ squeeze-updates main
deb http://mirror.its.dal.ca/debian/ squeeze-proposed-updates main
# See http://www.debian.org/mirror/list for mirrors closer to you

# Security updates (not mirrored)
deb http://security.debian.org/ squeeze/updates main

# Official backports repo for squeeze (I install the Linux kernel from it)
deb http://backports.debian.org/debian-backports squeeze-backports main

# Debian multimedia, a must-have for mplayer et al.
deb http://mirror.its.dal.ca/debian-multimedia squeeze main non-free

# Repo that provides latest Iceweasel (aka Firefox)
deb http://mozilla.debian.net/ squeeze-backports iceweasel-release