Debian – Where to find URLs for sources.list for debian for running apt-get update

Can anyone tell me where to find URLs to put in /etc/apt/sources.list for debian so that I could run apt-get update?

I couldn't find the precise answer by searching Google.

When I currently try running apt-get update I get:

W: Failed to fetch ftp://ftp.debian.org/debian/dists/lenny/contrib/binary-i386/Packages  Unable to fetch file, server said 'Failed to open file.  ' [IP: 130.89.148.12 21]

W: Failed to fetch ftp://ftp.debian.org/debian/dists/lenny/non-free/binary-i386/Packages  Unable to fetch file, server said 'Failed to open file.  ' [IP: 130.89.148.12 21]

I have no idea how to solve this.

Here is how my current sources.list looks like:

deb ftp://ftp.debian.org/debian lenny main contrib non-free
deb-src ftp://ftp.debian.org/debian lenny main contrib non-free
deb ftp://ftp.debian.org/debian lenny/updates main contrib non-free
deb-src ftp://ftp.debian.org/debian lenny/updates main contrib non-free

I'm running debian_version 5.0.8:

# cat /etc/debian_version 
5.0.8

Thanks!