Here is a sample for the Multiple CD installation: /etc/apt/sources.list
Line breaks and space constraints are not present in the original file.
#deb cdrom:[Debian GNU/Linux 5.0.3 _Lenny_ - Official i386 NETINST Binary-1 20090906-12:06]/ lenny main
deb http://ftp.de.debian.org/debian/ lenny main non-free contrib
deb-src http://ftp.de.debian.org/debian/ lenny main non-free contrib
deb http://security.debian.org/ lenny/updates main contrib non-free
deb-src http://security.debian.org/ lenny/updates main contrib non-free
deb http://volatile.debian.org/debian-volatile lenny/volatile main contrib non-free
deb-src http://volatile.debian.org/debian-volatile lenny/volatile main contrib non-free
There are other CDs/DVDs to be added as data source.
Become root and enter:
# apt-cdrom add
Message from the system (translated)
Please insert a disk into the drive and press Enter
Mounting CD-ROM ...
Identify...
Found 1 paketindex [...]
This is called: [...]
Writing new source list
Source entry for this Disk is: [...]
Umounting CD-ROM ...