Well, here's what the NEC says. All kitchens must have two 20 amp small appliance branch circuits that serve the countertop receptacles. It is ok for the refrigerator to be plugged into one of these circuits. It is also ok for the microwave to be plugged into one of these circuits.
But, it is not ok for a garbage disposal to be connected to either one of these small appliance branch circuits.
Here's a link that'll give you all sorts of details in how to wire your kitchen, it' will include the proper spacing of receptacles and all their requirements. Ask back with any questions.
http://www.selfhelpandmore.com/homew...dwel/index.htm