Key to everything involving painting is prep work. You can have the best paint in the world, but without proper prepping it will turn out like crap. I work for Sherwin Williams Paint and we sell Krylon Fusion and it seems to be a fairly good product. Depending on what interior pieces you are talking about, it would hold up fairly well. Fusion does not require you to prime, but I'd recommend it for something important like interior pieces which will be seen all the time. As for sanding, lightly scuff sand it cause a general rule for painting is to have a surface that is "clean, dull, and dry". You don't necessarily need to sand the hell out of it, just remove the sheen from the surface. Depending on what color you need, also look into an appliance epoxy (very durable but limited colors).
