Here's an unedit chapter I asked Mya Bell to critique for me. She provided a very nice example of what you can expect from an editor who performs a line-by-line edit of your work. Expect editors marks and comments within the contents of your manuscript.
I will enjoy spending my holidays editing this novel for content and grammar. But remember one thing, do as much self-editing as possible before asking (hiring) an editor to review your work.
I had to use a jpg file to get her online comments correctly.