The text of your book should go to an editor for a second look. As writers we get too close to our own work to give it an objective critique. When an editor reads your work for the first time, certain things stand out that might not be obvious to you after you've worked on the manuscript for months. Writers in the Sky can help you with that.
While the book is being proofread, you should decide how you want to publish the book. Here's an article I wrote that will help you know which publishing method is best for your book http://tr.im/ndVD.
Then, consider who you want to publish your book. If you plan to self-publish, you need to know about the cost of printing. I wrote an article about the costs of printing a color children's book http://tr.im/lsRm.