how to clear coat and paint truck.
 

i recently painted my truck with red acrylic enamel and no clear coat. i wanting to put a used bedside on it to look better and also paint just the outside of the truck black with a clearcoat for better protection. should i sand the used bedside then just primer it, then wetsand the whole truck including the bedside, if so, what size of sand paper should i use? After this do i apply the black paint? How many coats should i put on? Then how do i apply the clear coat? I've only painted one car in my life. Should i go with clear coat? I won't a good shine along with real good protection because it will get drove on a rock road some. Any help would be greatly appreciated.