AG hd wax is a very good product that's readily available, others to mention Dodo hard candy is good as is Swissvax Onyx, its depends a lot on budget and time, if ease of use is important then Onyx is the one, my personal process is :
Wash and dry (using the two bucket method and a wash mitt, dry with good quality microfibre towels)
Clay treatment (make sure you get a mild clay as there are different grades and the wrong clay can marre your paintwork, dodo's basics of bling and born slippy lube is very good as is AG's, the clay is the safest way to remove road tar from your paintwork, but if you come across a large blob of tar then a quick squirt of tar remover on the affected area alone and a wipe with a clean microfibre will do the trick but don't rub!!
Treat the bodywork to a good pre wax cleanser, Swissvax cleaner fluid regular and Dodo's Lime Prime are very good, use with a terry applicator pad, in straight lines only, no circular motions!
Then apply your wax of choice, with the wax, light layers are the way to go, just so you can see a film of wax on the paintwork, leave to cure, generally 10-15 mins, wipe off with a soft microfibre and buff with a good quality cloth, Swissvax micro polish or Poorboys super thick and plush towels are very good.
Hope this helps :driving:
Remember as with everything......................LESS IS MORE!!