I love driving a clean car so I've spent alot of time trying different things, taking to people that know paint and paint care products and talking to guys that detail cars for a living. A few years ago I worked P/T at my friends detailing shop. I really enjoyed it, but I'm a bit too busy these days to get in there and get my hands dirty. The last cars I detailed were being prepped for display @ Speed-o-Rama in Toronto.
The following stuff works for me. If you disagree I'd be interested to know why and if you have any questions fire away.
Washing
The first thing I do is rinse the car down. I use low pressure for the body and high pressure for the doorjams wheels/wheel wells and chassis.
You should use a good car wash soap (I use Maguires, but they're all pretty good). Use a good amount of soap, as it works almost like a lubricant so any dirt left on the car won't be abrasive. Don't use dish soap. It's too harsh and it will strip the oils out of your paint. After washing with dish soap or other detergents a few times the paint will look very dull.
I use a CarBrite wash mit. The idea when washing the car is to use something with a deep pile so the dirt has some place to go. With a sponge the dirt sits right on the surface of the sponge and being dirt, it's abrasive.Stay away from the sponge! A 100% cotton cloth is great too, but I tend to save them for wax and polish.
Start from the top and work your way down. Don't wash your car using circular motions. Go back and forth with very little pressure. This will prevent swirls.
Rinse the car with low pressure front the top down. Let the water's "sheeting" action rise the car off.
Drying
I use a natural chamios to dry the car. They're expensive, and if you don;t take care of them they don't last long, but they work
very well if you use them correctly and take care of them.
Wet the chamios, gently wring it out and lay it out flat on the car. Pull it towards you to colect the water, gently wring it out and start over. Don't go nuts wringing it out or it will develop little holes. Wash and rinse the car well. Don't use the chamios to collect any soap left on the car, it will dry the chamois out. Don't use the chamios on a part of the car that isn't clean, You get dirt.grease on it and reduce it's life.
Polish and Wax
That's a whole other subject. I could go on and on regarding different products to use, but I'll stick to technique. Park the car under cover, away from sunlight and make sure the paint surface is cool. This will keep the wax from baking onto the paint. If the wax bakes, it will take alot of effort to remove and you end up putting swirls into the paint in the process of removing it.
I use a clean dry deep pile 100% cotton cloth, cut into rectangles and folded into squares. This gives you 4 clean surfaces to work with. I put the wax on in gentle cricles (to fill any swirls) and take it off in straight lines using minimal pressure. To remove the wax use a high quality 100% cotton towel. Don't let too much wax build up on the towel. Keep turning it so you have a fresh surface.
You can wash the towels often and just trim then down a bit to get rid of loose threads.
How long I leave the wax on depends on the weather. It should "set-up" and haze over, but you shouldn't let it get too dry or you'll use too much effort to remove it, creating, you guessed it, swirls! If it's very humid out the wax will take a long time to set up, be patient.
I polish the car each spring and wax it every 2 or 3 months. Regarding polishing, remember that paint cleaners and polishes remove dead paint from the surface. The key here is that you are removing paint from the car! Avoid excessive use of cleaners and polishes by maitaing a good coat of wax on the car. Clean and polish too much and the car will look dull and you might even wear throught the paint on some areas!
I clean the paint on my cars only once! After that, like I said, I polish it in the spring and maintain the wax every 2 or 3 months as needed.
A few other things...
Use newspaper to clean your windows. It's cheap, doesn't streak and it's lint free! Spray the glass with Windex or whatever and wipe it with the newspaper.
Buy a cheap 2" paint brush and cut the bristles down to about a 1/2". This is great for detailing the interior of the car. Dip it in a bit of soapy water and clean the vents and any other nooks and crannys that you can't hit with a cloth!