How the Pros Edit: A Checklist for Sanity
I trained as an editor for eighteen years. Both as a freelancer for various publishers and a salaried manuscript editor for a small press in the Midwest, I worked with experienced pros who were steady, careful, and kind enough to instruct me.
Once you've finished your book, put it aside for a week or two. However, not too long. If you put it off for longer than a couple of weeks, you're never go back to it, if you're a new writer.
Here's why: editing can be scary when you'v never done it before. Although it will get easier with each book, it's HARD to slash words you sweated to get onto the computer screen.