Most everybody here has given fantastic advice! I have been detailing cars for a very long time and I would suggest a few tricks to also help out.
First the clay deal- fantastic idea- I use it with the Meguiars spray wax with the clay
Micro fiber rags- I live by these things. You don't have to go expensive with them, here in the states I pick them up in bulk at target.
I use a dewalt variable speed buffer. I use cotton pads and the foam pads. I keep the speed at its lowest setting unless I'm trying to heat up an area to get rid of scratches I'm too lazy to wet sand. The cotton pad works best for me on an initial buff.
The products I have been the happiest with have been the 3M line.Finesse it and perfect it. I have never tried anything else. http://solutions.3m.com/wps/portal/3...be4GPDZ0ZJTCgl
As far as the buffing, I suggest that you place a hunk of cardboard over the cowel of the vehicle and if the vehicle has any black or exposed trim that is rubber- use blue tape to cover them. These is the easiest areas to quickly burn through.
The deal is to go slow and be consistent- I do a panel at a time.
If the vehicle is heavily oxidized- take a spray bottle and keep the surface wet as you buff, not my favorite method but sometimes the paint calls for it, mostly on older non clear coated cars. It makes a huge mess either way.
I normally keep the buffer flat but as you get comfortable with the machine and understand what is going on, you will get a feel for using the pad on a bevel.
Stay away from the crisp edges and or panel changes, first time out- you run the risk of burning the paint.
Not knowing your skill set- I will go into it a bit more. Do your roof first and move down from there. I do the hood last as it always seems like I have to start and move the car after washing. You want to stay away from a hot surface. I do the sides next and then the trunk and then the hood.
I do it in this way whether I clay the car or not. Not every buff requires a clay.
Another point is that if the car has any black areas where you are going to apply any silicone type of material or if you spray the tires and wheel wells, do all of this before you hand wax the car. The wax will get rid of any LIGHT overspray.
I then hand wax the car starting with all the jambs first and them move from the top to the hood and trunk.
I don't normally put any of this information out there because there is always someone who knows better- Like I said before I have been detailing cars as a hobby and professionally for the better part of 15 years, this system is what works for me and my very select clients. Are there other ways of doing it....yes, but this is how I do it and I hope it helps.