First go under VIEW then select SHOW----GRID. The grid will be very useful in separating the quadrants. Next, using the Slice Tool set on FIXED ASPECT RATIO you should be able to select quadrants of the image (know the dimensions ahead of time or use the grid to guide you to equal sections). You can select the slices as their own layers or whatever you want to do with them.

Edit: I tried a test of my own and it appears that you can double click on each individual slice and hyper link it or add some kind of attribute to it. I'm more familiar with this process in Flash or Fireworks though. Its been a while.

What'd I'd probably suggest is a combination of this and firebane's suggestion. Use the grid to make equal sized selections of your image and save them as individual images.