First and foremost preventative measures are the best. Obviously your car is not in perfection condition so preventative wont make your car any better right now. Get a good detail (cough reflect effect cough) and get Optiguard (aka opticoat) paint protection.
Then the following is a good start for prevention of swirls.
Use grit guards in the buckets
Get a high quality wash mitt such as the Car Pro brand one that Hamish recommends -
http://www.carpro-us.com/merino-wool-wa ... ors-tools/Use 3 different wash mitts, one for wheels, one for upper portion of the car (roof, windows, boot, bonnet, tops of side quarter panels) and the 3rd wash mitt for doors, bumpers and lower quarter panels.
Learn proper washing and drying techniques, don't use force, you are supposed to let the wash mitt / drying towel glide over the paint.
Also a high quality Waffle weave drying towel like the Optimum one -http://optimumcarcare.com.au/product/51/optimum_microfibre_waffle_weave_drying_towel.html