Right in short, althou painting the car then the panels after should be ok, you can have problems with the paint matching even using the same batch which can be caused by pressure diffferences at the gun, distance u spray at, speed, temperature etc etc!!! Alot of places do like to paint the shuts first then soft edge the doors and paint the whole car with the panels on to get a good match!! Althou obviously u can do it either way.

Never used the pre paint wipes either, its best to use a proper degreaser and then tack rag to get any particles off prior to painting!! Dont forget if you use a waterbased basecoat u have to use a waterbased degreser, and when u have mixed the paint/lacquer make sure u have filtered the paint thru a strainer at least 400micron or 125micron.

Prep wise u gonna do it dry or wet?! Guessing wet?! If the bodywork is ok and u want to do it wet flat 600 wet and dry is ok or 800 as your going to prime it first, 2 coats should be sufficient to cover, 3 if your worried about breaking thru. Then to finish 800 wetflat will be ok, just make sure you dont leave any scratches etc and take ur time, and a grey primer is best as it will take less basecoat to cover with moonstone blue

Application wise once clean and degreased just make sure u have a good gun to use, devilbiss is my personal fav, and if ur using waterbased 1-2coats should be ok with a drop coat, or solvent 2-3 with a drop but all depends how well it covers etc and what the manufacturer reccomends!! If using a high solids lacquer then a grip coat and full coat is enough, if you put it on light thou then add another, with medium solids 2-3coats should do it!!

Spraying wise u need a big compressor thou mate as u need a good constant 2-2.5bar of pressure and ideally an pre filter to stop any water etc getting thru to the paint from the airline!

Goes without saying, you need the garage to be at a good temperature, ideally most manufaturers recomend 21degress but basically not freezing cold!! needs to be wind free and if the floor has dust etc would pay to wet the floor first before spraying to keep the dust down!
Then the main thing is to make sure the paint has dried between each coat, and its applied the same.

Just bear in mind thou and not trying to put u off but, pretty much most garages will charge u even more to fix fuck ups from DIY paintjobs as they would have to strip off what u have done if its bad enough!!!

But if u feel like doing it mate, go for it!!