The sources.list file includes the list of packages that can be installed on the system.
Below is an example ubuntu dapper one
----------------------------------------------------------------------- # Ubuntu supported packages # GPG key: 437D05B5 deb http://gb.archive.ubuntu.com/ubuntu dapper main restricted deb http://gb.archive.ubuntu.com/ubuntu dapper-updates main restricted deb http://security.ubuntu.com/ubuntu dapper-security main restricted deb-src http://gb.archive.ubuntu.com/ubuntu dapper main restricted deb-src http://gb.archive.ubuntu.com/ubuntu dapper-updates main restricted deb-src http://security.ubuntu.com/ubuntu dapper-security main restricted # Ubuntu community supported packages # GPG key: 437D05B5 deb http://gb.archive.ubuntu.com/ubuntu dapper universe multiverse deb http://gb.archive.ubuntu.com/ubuntu dapper-updates universe multiverse deb http://security.ubuntu.com/ubuntu dapper-security universe multiverse deb-src http://gb.archive.ubuntu.com/ubuntu dapper universe multiverse deb-src http://gb.archive.ubuntu.com/ubuntu dapper-updates universe multiverse deb-src http://security.ubuntu.com/ubuntu dapper-security universe multiverse -----------------------------------------------------------------------
If you are using Plesk it is a good idea to include thePlesk .deb repository with in the sources.list, below is an example forPlesk
8.6.0
----------------------------------------------------------------------- deb http://autoinstall.plesk.com/ubuntu/PSA_8.6.0/ dapper all -----------------------------------------------------------------------(you can check what version are availble by visiting http://autoinstall.plesk.com/ubuntu/ )So a complete sources.list file for - Ubuntu Dapper - Plesk 8.6.0 would be
-----------------------------------------------------------------------
# Ubuntu supported packages
# GPG key: 437D05B5
deb http://gb.archive.ubuntu.com/ubuntu dapper main restricted
deb http://gb.archive.ubuntu.com/ubuntu dapper-updates main restricted
deb http://security.ubuntu.com/ubuntu dapper-security main restricted
deb-src http://gb.archive.ubuntu.com/ubuntu dapper main restricted
deb-src http://gb.archive.ubuntu.com/ubuntu dapper-updates main restricted
deb-src http://security.ubuntu.com/ubuntu dapper-security main restricted
# Ubuntu community supported packages
# GPG key: 437D05B5
deb http://gb.archive.ubuntu.com/ubuntu dapper universe multiverse
deb http://gb.archive.ubuntu.com/ubuntu dapper-updates universe multiverse
deb http://security.ubuntu.com/ubuntu dapper-security universe multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu dapper universe multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu dapper-updates universe multiverse
deb-src http://security.ubuntu.com/ubuntu dapper-security universe multiverse
deb http://autoinstall.plesk.com/ubuntu/PSA_8.6.0/ dapper all