Whether you’re sending a manuscript to an agent or publisher, submitting a short story to a magazine, or independently publishing your work, you owe it to yourself and your writing to work with an editor.
Consider this: before any traditionally published book appears on the shelves, it passes through three editorial phases. Upon acceptance, the manuscript is edited for content (pacing, consistency, plot and character development, voice, etc.) Before it is typeset, the manuscript is copy edited (typos, spelling, grammar, punctuation, etc.) Once typeset, the pages are proofread (typesetting errors, format, references, pagination, etc.) The book passes through each of these stages at least twice to make certain that errors found in the previous pass were corrected.
I offer editing and proofreading services on a freelance basis. Most of the writers I work with pay out of their own pockets, so my fees are very modest by industry standards. I am always happy to talk with other writers about their projects, even if they choose not to engage my services.
View my LinkedIn profile at:
http://www.linkedin.com/in/jenniferbarricklow
Still skeptical? Read what Carol Fisher Saller, senior manuscript editor at the University of Chicago Press, has to say about editing in this excerpt from The Subversive Copyeditor.
The Daily Compost 
Just saw this after I posted my offer to send you chapters “for fun”. When I engage an editor, it will be you, as I know what kind of work you do. Excellent, meticulous work. This is my testimonial to your talents!
Thank you! Very high praise indeed, coming from you, and I would be honored and delighted to work with you.