Hi Gravity!
Do: Go to North American Motoring (NAM) and read the detailing section about clay-barring.
Do: Get a Meguiar's claybar kit. It includes a "quick detailer" spray and carnuba wax. Get it at Wal*Mart for $10 less than auto parts stores sell it for.
Do: Order some Prima Mystique (car wash), Prima Hydro (killer quick detailer stuff), Prima Epic (great polish) and Black WOW (great stuff for keeping the black plastic stuff black instead of gray) from Detailer's Paradise. Links on NAM detailer's board.
Do: Follow all directions as to use of the above products to the letter.
Do: Get some stuff called RejeX from
http://www.corrosionx.com. Use it on your rims. Clay bar them too BTW.
Do: Plan on spending hours and hours doing all of this stuff the first time.
Don't: wash your Mini with Dawn, Palmolive or other such detergents. They strip wax off of the car.
Don't: Wax/polish your Mini with lesser products.
Don't: Do any of the above cleaning/polishing/clay-barring in direct sunlight. Particularly when wearing shorts for the first time (outside) in 25 years and sit on the ground in direct sunlight causing 1st degree burns on the inside of your legs. That is, unless you're a glutton for punishment like me...

Don't: Park your Mini where the pterodactyls that live in my neighborhood can find it. Particularly when they've been eating blackberries.