Enable autocompletion in apt-get and bash

First install the following:

apt-get install bash-completion

Now, you need to load bash completion every time you login to your shell, by adding the following to your profile or .bashrc:

if [ -f /etc/bash_completion ]; then
 . /etc/bash_completion

If you need to get suggestions for command not found, install:

apt-get install command-not-found