Welcome to AGO

Thought I'd answer your questions too seeing as I'm bored..
Machine polishing Vs Hand polishing - You will achieve a much better result with a machine. You will only be able to remove very very light scratches/swirls by hand, but with a machine you will be able to remove pretty much all of them if you know what you're doing.
Advantages of hand polishing - You can't burn your paint, that's pretty much all I can think of for advantages lol
Disadvantages of hand polishing - Takes longer, only minimal swirl removal can be done, your arm will be sore
Advantages of machine polishing - You'll be able to remove a big majority of the imperfections in your paint, and alot faster
Disadvantages of machine polishing - More expensive then hand polishing, and you can burn your paint if your using a Rotary and you dont know what your doing
NOTE : The Porter Cable 7424 is not a rotary and you cant burn your paint with it
Washing - Try wash your car in the morning when the sun isn't out and its cool, or at night time.. Don't wash it when its hot because the water will just dry and cause waterspots..
Detailing process :
1 - Wash
Wash your car with a proper wash mitt and shampoo. Use 2 buckets, one with your soap water mix, other with just plain water. Start by doing the roof, then the hood, then the boot, then the doors, then the bottom of the car etc.. Make sure to rinse your mitt in the plain water bucket after every panel to remove dirt, so it's clean when putting it into the other bucket.
After washing dry with a good drying towel such as the Guzzler
2 - Clay
Use a claybar with lube to remove surface contamintents. This will make your paint smooth and ready for polishing or waxing.
3 - Polishing
Polishing will remove swirls, scratches, waterspots etc..
As I dont know what polish your going to use I cant really help you much more, but if your looking at buying Lake Country pads I can help you there.
Lake Country Yellow Pad - Heavy cut pad. Will remove heavy swirls, oxhidation etc. You shouldn't need this pad very often.
Lake Country Orange PAd - Light cut pad. Will remove most swirls depending how bad they are. In most details I've done I've only had to use this pad as it usually removes most imperfections, like I said, the Yellow pad isn't needed much.
Lake Country White Pad - This pad has very low cut. Use it to apply polishes to remove hazing/marring from more abrasive polishes.
Lake Country Green Pad - This pad has no cut. Use it to apply paint cleaners, glazes etc..
Lake Country Gray + Blue + Red Pad - All these pads are finishing pads. Use these to apply waxes, sealents.
Well I think that sums up all your question, now I need to take a break because my fingers hurt haha..
