I can highly recommend Debi's self-editing course. Freaked me out at times when I realised how much more work I needed to do! Apart from Debi's amazing assessment of work and comments, there is also a lot of reference material provided.
Another Self-Editing alum here with a hearty recommendation. I was a young writer (in experience, not age) and naively thought my writing was nearly ready for pub. The class showed me otherwise. It was a much needed splash of ice-cold water for me. The hardest lessons provide the greatest reward. Those lessons propelled my writing forward.
I'm a self-editing course alumni as well and benefited greatly from the course. It is well worth doing as the course content, the tutors and the feedback from fellow students all help. The tutors are so helpful, knowledgeable and supportive - I learned heaps :-)
Hiya, I've just started the course. It's paying dividends already. I sent the first draft of my MS to Debi over a year ago now mainly because I didn't have much previous writing experience and didn't feel ready for a course. I worked through the recommendations as far as I could by myself and read several teaching books. Week one has just launched and I'm finding it eye-opening already; my to-do list is growing nicely. Don't know if that helps but contributing just in case it does. Good luck with your MS!
Just a vote for manuscript assessment. I haven't done the course, and perhaps I should, but the manuscript assessment I received via Jericho was amazing! Even after 7 reads by people I know and one free read by an agent as a favour, I never got anything as thorough and thoughtful as what I had via the assessment. I think you can lear a lot with either choice.