type and color of paint you would recommend: SPRAY paint--browns, black rust...yes wipe top of rails. Good method: use liquid track cleaner and apply to the section of rails you want to paint. Spray the rails. Immediately wipe off the top of the rails. APPLY YOUR BALLAST FIRST BEFORE ANYTHING.
Laying track...easy...attaching it is another story...if you get Gargraves WOODEN TIES drill a pilot hole for the screw that will secure the track to your surface. Gargraves does make 1 inch long track screws. Also, don't over-tighten these screws because you will damage the wooden ties. If you don't drill the pilot hole, you will break tie after tie.
The most challenging task is bending Gargraves flex track. There are many recommendations/suggestions. My advice is whatever you do, do it s.l.o.w.l.y. I actually hold the flex piece against my chest and begin "fitting" it around my chest slowly bending it into a curved section. It will take, practice, patience and time to perfect your own technique. IF YOU DON'T OWN A DREMEL ROTARY TOOL, BUY ONE NOW. You need it to cut track rail without smashing the tubular rail flat. PRACTICE on crappy piece of rail.
Look on youtube for how to videos...hundreds.