I am working on a guide to proper car washing, though it may be some time before I am finished. It will be good, don't worry, I am going to pack this thing full with as much pertinent info as possible. For now, these articles are a good start to proper vehicle appearance maintenance.
How to Properly Wash and Dry a Car
Automotive Paint is Delicate - Don't Touch it!!
The Grit-Guard 2x4 Wash Method