skimming plastering onto damaged / flaky plasterboard

[jamieb1]

Ive recently started stripping wall paper off one of my bedroom walls & realised that the wall underneath is a complete mess. I am now left with a wall which is a mixture of exposed plasterboard, the old skimmed layer before the wall paper obviously went on & areas where the steamer has taken off the paper on the board. To top it all off I put on new skirting boards & put up new coving before I thought about doing something with the walls.
Can anyone PLEASE recommend what I do to get a clean finish on this wall, ie is there any DIY products (excluding Polycell smooth it stuff) that i can use to get a clean finish to paint or should I get in a plasterer (Would they be able to sort it?)
The other walls in the room still have paper on them can this just be plastered over to save the hassle above?
Thanks

[thedoctor]

Skimming is your best answer for a good clean finish Jamie and never plaster on top of paper. Any surface, whether its paint, plaster, timber etc is only as good or solid as the surface its fixed to and if you plaster on wallpaper which is held up bt a water based adhesive you are soaking the paper, and adhesive, with water again. Once the paper comes unstuck the lot falls down.