Here is a really fun project I worked on with North Face, NORTH FACE YOUNG EXPLORERS GUIDE. It's an activity book illustrated for kids all about the great outdoors (camping, exploring nature, etc). Here are a few illustrations and hand lettering examples from the book.
Hand Lettering for Front and Back of book
Some cover concepts
Some hand lettering options
Some characters to be used inside the book like the images below
See more kids related illustration here