Annoying surface

I am about to embark on painting one of our bedrooms but it seems the previous owner lazily removed a border and then just painted the wall without removing or repairing the damage caused on removal (just painting over). Anyone have any ideas on what I should do? My first thoughts was sand as much as I can then put a skim coat of plaster repair over it then finely sand again. Would I be correct or should I just go straight to the skim without the initial sanding. Any other ideas?

 

Welcome to the forum.
Depending on how bad the damage is, and how much time you are willing to spend, you could go the direction I did on one of my boy's rooms in the old house.
What I had done was roughly go over the wall with a random orbitting sander just to knock off any loose paint or bumps (there was a few spots that had paint drips from many years prior).
I notched out any cracks in the plaster and repaired them with mud. Filled any nail holes, etc as well.
Once that was done, and everything was cleaned up, I used a good primer to clean up and hide any of the remaining imperfections. A lot of the small spots I had repaired probably could have been hidden with the primer as it was pretty thick and was great with hiding things.
Once done, paint of course.

This may or may not be the easiest method, but it worked for me.

 

Mike pretty much nailed it although I wouldn't bank on primer hiding any defects. If the wall paint is flat latex - sanding is optional. Sometimes scraping off boogers works better than sanding. Joint compound will fix most of it. Are your walls plaster? or drywall?