Sanding Surfaces to Prep for Painting

"O.k., to prepare our boards now we're going to lightly sand them with a finishing sand paper; this is a 180 grit sand paper. And you just want to lightly sand it all over. All of the panels, you want to make sure you do the sides, and the fronts, and the backs and all the sides just to prepare it for painting. O.k., I finished my sanding; notice I'm working on a work surface here. For easy clean up I've opened up a plastic bag, a large trash bag and laid that down on my table; and I'll be able to wrap that up and throw it away. Now when the sanding is finished, you want to take a rag and wipe down your project so there's no dust on it at all. Make sure you get all the sides and then you wipe that down. And you'll want to put down a new work surface before we start painting."