Things to understand -
Choose a good soap. Many soaps on the market advertised as "car shampoo" actually strip and degrade waxes and sealants. Our soap is perfectly pH balanced so it will never strip or remove your wax.
Depending on how much time you want to dedicate to it and what products you're using you can throw a quick coat of wax down whenever you wash, but that might be a tad excessive. I personally refresh my coat of wax every 2-3 washes, obviously how many miles you drive, the conditions in your area, and the product you use will dictate if thats often enough for you.
You only need to clay again if the paint gets heavily contaminated (water spots, rail dust, paint overspray) or you start to notice the paint is rough. Theres a quick and easy way to tell if your paint is ready to clay... its the plastic bag test:
Scratch Removal
If you clay the car you will be pulling all your wax/sealant off... the clay will remove it so you will need to go thru the full process again once you clay. Generally an average care only needs to be clayed a couple times a year at most so don't over think it.
Hope that helps, shoot anymore questions out if you have them.