Setting the resolution for the console is not much of a concern normally. Your virtual terminals are set to a reasonable resolution by default on a normal Ubuntu desktop installation. If you run Ubuntu server in a virtual machine, however, you are stuck with 640×480 resolution.
Recent versions of Ubuntu all use Grub2 so the way to change the resolution is now:
sudo vi /etc/default/grub
Then add the following:
GRUB_GFXMODE=1024×768
GRUB_GFXPAYLOAD_LINUX=keep
Save the file and run:
sudo update-grub
On your next reboot, there it will be.