Goodnight Moon, Margaret Wise Brown, Harper Collins.
Alas, Summer is over and it's Back to School time. Your chidren might be all fussy because they don't want to go to sleep. If you don't already have Goodnight Moon, this is very simplistic read to get them ready for bed. Sure the pictures seem like they are from another time, but there is a rhythmic type flow of the story that captures all the children we have read it to.