Listing packages in Console

[Alfred Vahau]

Hi,
How can I list the packages that are available in command-line?
Under custom-installation, one gets a console from which one one
can install the packages selectively. As I've learnt, the command for
installing packages is

sudo apt-get install package-name

But how do I list the package names to select from?
In particular, I want to install packages relating to a minimal desktop
display.

Issuing a startx command results in a Display Not Set error message.
sudo apt-get install genome as a trial does nothing because there is no
package by the name of genome. It's called something else.

sudo apt-get install Firefox also results in a Display Not Set message.

I also tried a default installation which installed a lot of packages and
I tried to remove the unwanted ones using Synaptic PM. Unfortunately
some of the dependency rules were broken and I found myself in the console
mode, unable to get back into the Genome desktop.
Ctrl+Alt+F1 and Ctrl+Alt+F7 did not have any effect.

Thanks in advance for the assistance.

Alfred,