Add an X11 server
First make sure that your kernel supports "userspace software suspend". If it doesn't (as might be with a homegrown kernel), then reconfigure your kernel to include CONFIG_SOFTWARE_SUSPEND=Y, recompile, reboot.
Now, log into the real console of your server. If you use a terminal, the setup of X will "hang" at the end.
You can update your apt using
apt-get update
Now run
tasksel
Under Choose software to install, remove all asterisks except for "desktop environment". When you select OK the system gets going. After installing a LOT of software, Tasksel will ask you what you want your default resolutions to be. Select at least those that you want to be able to use. Then Tasksel installs and configures some more.
However, since this will make your server start up with a GUI, we now take out the graphic desktop manager with
update-rc.d -f gdm remove
This means that you still boot into the text mode console. So how do we then get that graphic desktop (should we ever need it)? Simply by issuing
startx
at the root prompt on the real console.
That's it!