I'm trying to create a web homepage with graphical regions that are
clickable.  Each graphic would change color when you roll over it.

Before I go too far down the wrong path, can you let me know what the
"best practice" is for doing this.  My inclination is to:

1. create the entire page in photoshop as a single graphic
2. save it as a separate file and modify some of the background colors
for "roll over" colors
3. flatten both images
4. cut them up into pieces representing the clickable sections
5. create a grid in dreamweaver and paste each section in as a rollover image 

Is this the right approach or am I missing some obvious short cuts.

Many thanks!

It would be very simple if you have Fireworks. Otherwise, it is the right approach.

I agree. Fireworks would be best. I've created entire websites in Fireworks before.