While preparing to submit some picture book manuscripts to agents and publishers, I looked up industry standards online. Although there seem to be variations in preference, I found the following articles to be helpful and hope you will find them equally useful.
“Picture Book Standards: 32 Pages” by Darcy Pattison: http://www.darcypattison.com/picture-books/picture-book-standards-32-pages/
“Formatting Your Manuscript” by Pat Sherman: http://www.writingpicturebooksforchildren.com/manuscript-formatting.html
“Manuscript Format Basics” by Harold Underdown: http://www.underdown.org/manuscript-format.htm
“16 Manuscript Format Guidelines” by Simon Kewin: http://www.dailywritingtips.com/16-manuscript-format-guidelines/
“Writing a Cover Letter” by Pat Sherman: http://www.writingpicturebooksforchildren.com/cover-letters.html