Patching and Plastering - Painting walls that have had paneling removed

I just removed paneling from the bottom half of my dining room. The paneling had been glued and nailed. Now the drywall, which had previous to the paneling, been painted, has nail holes, lines of glue in some places and in some places the top layer of the wall stayed with the glue on the paneling and so there are big lines where it looks like cardboard (the underlayer of the drywall) on the walls.

I think I need to do some kind of skim coating (which I've never done before). How should I approach this?

Any advice appreciated. Thanks

Welcome to the forums!

Once all the glue and any loose paper is removed you need to coat the area with an oil base primer. This will prevent the moisture in the mud or paint from further loosening the paper. Skim coating is fairly simple, take joint coumpound and thin it slightly, then neatly smear it on the wall with a broad knife. You don't want to apply it thickly [especially if not experienced] A thin coat is easier to controll, sand when dry. Repeat as needed.