If you want to look after your paint work, change your washing habits, use the two bucket with grit guards and a wash mitt method with a pH neutral car shampoo.
When it comes to polishing your car, use a clay bar to remove the contaminants from the paint work that the washing missed, leaves the paintwork glass smooth.
Then polish the car followed by a wax. Hand polishing wont take that much paint off, but if you are that concerned then you could always buy a paint thickness meter.
Have a look at some detailing forums to get an idea of the products to use.
You will be astounded by how long it can take and how much money you can spend detailing your car, to get it looking pristine.