How set desktop/resolution for xwindows?

[André Bell <debian2@one-click.com>]

How do I set the resolution for xwindows applications?

I know with win95 I just right click on the desktop and resize it.  But
with my debian installation my applications are too large for the screen
and I have to scroll up, down, left, and right to see the rest of the
screen  -- what a pain!

I've tried formatting and repartioning and reinstalling debian to see if I
missed a step during installation and I can't figure what I setup incorrectly.
Please help.

Thanks!