Photoshop help!!

[CanuckAmok]

I am a complete simpleton when it comes to Photoshop. Can somebody help me?

I want to make a bumpersticker template because I got railroaded into a project for the Legion...

15" long and 4" high

The design would be divided in half horizontally, effectively making two sections of 15" x 2", one "on top of" the other.

I want to be able to set it up so I can select different colours for the background of each section, and then write in coloured text over each background. example: top section yellow background with blue lettering, bottom section blue background with yellow lettering. OR, top section with black lettering on a red background, and bottom section with white lettering on a black background.

Sounds simple, right?

Wrong.

I can't even divide and colour the backgrounds. I suck.