I'm sure Haynes do a book on bodywork .. or check the local library. I've resprayed a couple of cars, but it's a bit much to write up in detail on a forum.
Rub it all down to take off the old lacquer and flatten off the old paint pretty much as far back as you can. If you go down to the metal don't worry. Sometimes it's best to take it ALL off. (Every watched American HotRod on Quest? They acid dip or sandblast the bodies if they can .. not so easy on a monocoque chassis). Get rid of rusty patches, etc. Make sure these are well treated or they will come back!
Fill dings and deep scratches, rub down, repeat several times, until as smooth as rest of car. Replace panels that can't be repaired ...
Mask up everything you don't want painted, unless you remove these parts (lights, handles, etc). Lots of masking tape, card/paper, etc.
Lightly spray car with a dark colour on light car/light colour on dark car to act as a guide as you are going to rub it all down again and look for high and low spots.
Use a rubbing block not just your hand or your fingers will cause very light ridges.
Repeat filling and light coat steps above until perfectly flat.
Base or under coat.
Rub down ... wet & dry on rubbing block and soap and water... repeat undercoat. Paint work needs to be as smooth as a babies backside or every bump will show through the top coats!
Rub down one last time to give paint a "key" to stick to. Medium wet & dry and soap and water.
Spray base colour thinly ... rub down. Repeat as many times as necc until car is covered and looks smooth as that babies ar$e again! Don't try and do it in one or you get runs and "orange peel" ...bumpy paint work.
Rub down with a very fine wet&dry (1800,2000 grade) with soap and water until paint is smooth.
Lacquer coats ... several ... lots of rubbing down with the finest w&d you can get and soap/water. At this point it's light rubbing the car down with a wet lettuce leaf ... and you will have the smoothest hands in the street!
Then lots of polishing once the paint has had a few warm days to harden ...
For plastic parts, use a special plastic undercoat to give a good base for paint to stick to ...
Put you off yet?
This isn't a definitive guide but the main steps as I remember them. Most of the time is in the preparation. That 80/20 rule ... 80% prep/20% painting ... slow, boring, hard work ... but so worth it!
And weather should be warm and dry!! Damp will play havoc with wet paint and lacquer.
Phew ... did I just write a guide?