apt-get - how to update, upgrade

It is not necessary that apt-get fetches the latest versions you needed always. You have to update the list of places from where new versions can be fetched.

It works like this:

apt-get looks at:

/etc/apt/sources.list

You have to update that file with proper links:

This post explains it well: https://help.ubuntu.com/community/Repositories/CommandLine

remember Ubundu 8.xx is called hardy, other versions have got different names.. find out and use accordingly.
use: "cat /etc/issue" or "lsb_release -a" to find out the version of linux u r running

once updated the list use
man apt-get to know how to update and upgrade the version list.

then use apt-get install .... to update your libraries with the new versions.