Do you have a snow foam lance? You will need one of them to go with the pressure washer if you want snow foam.
As for foam recommendations, I have used a few. My current foam of choice is GYEON Q²M FOAM. Not cheap, by any means, but it is excellent. I have previously used Meguires Hyperwash too, and it is also excellent. These snowfoams I generally buy in 4 - 5L bottles, stick on a pump action nozzle thing, and use 2-4 pumps per snow foam bottle. Gets a nice, thick foam.
As said above, that's a pretty good start on the procedure. But it really depends on how far you're willing to go, and how much time you can invest. Last time I did my car, it went something like this:
Rinse
Snowfoam (Gyeon Q2M Foam)
rinse
bucket wash (Gyeon Bathe)
rinse
Bug and tar remover (Autosmart Tardis)
rinse
fallout remover (iron out etc...)
rinse
claybar (I use Meguires bar, but have a G3 Clay Mitt too)
rinse
polish (Usualy AG SRP if I'm not too worried about finish, but last time I tried the GTechniq P1. Also have Mezerna cutting compounds if required, and finishing polishes / glazes. I do have a DA polisher though)
wax (Bilt Hamber Double Speed Wax)
sealant (Mezerna PowerLock)
glass treatment (this has it's own procedure, so wash, dry, glass cleaner, polish, IPA, Gtechniq G1/G2).
Wheels (Again, depends on how far you want to take this, fallout remover, claybar, polish, wax / sealant).
Took me about 2 days to get all that done, but I take regular breaks / have other stuff to do / usually only working in evenings.