Painting and grotty plasterwork. Any tips?

[chartreuse]

We have bought a do-er upper, the entire ground floor needs builders in, but the bedrooms just require redecoration. The plasterwork is uneven, gouges out of walls etc but the builder thinks that a good decorator will be able to remedy that rather than needed a skim of plaster as I had thought. He thought that sanding down/filling in the rough areas would be sufficient. I've done my fair share of painting over the years, so I'm going to give it a try but I wonder if anyone has any tips or links to blogs that might help?