I blogged today about how long it takes to get from the idea for a book to the actual book on bookstore shelves -- and it's probably a lot longer than you think! Go to my latest blog post on Sci/Why for all the gory details.
And browse the archives at Sci/Why for lots of interesting posts related to science and books. I am one of a group of Canadian kids' science writers who have been blogging at Sci/Why for several years now. At this point, there are well over 500 individual posts, all of them (she said, modestly) well worth the time to read.