Publishing isn't all about the writing and the cover! Here are some people who offer help with other aspects of the process that I can recommend. Click on their names to go to their websites.
Teaches a class that takes you from idea conception through your first week of completed book promotion. It's structured so that you can work through the assignments while you're in the process of writing, or if you've already written a book, you can immediately move into the publishing and marketing process.
All types of editing
I've compiled a list of illustrators who might work well for your children's book project.