There are a couple of books that I love to read to my kids, so I'm going to mention them here.
"How Do Dinosaurs Say Good Night" by Jane Yolen. My sister bought this for us some years ago. There is also a similar "How Do Dinosaurs Go to School". With a side appearance by one of our cats.
It involves all the things that dinosaurs do before they go to bed, whining to hear another story, stomping feet on the floor, etc. In the end, they don't do any of those things, they hug their parents and go to sleep....I'm not sure my two have figured out the plot just yet, but they're getting closer.
"Dr. Seuss' Sleep Book". I love how he says things like "what a fine night for sleeping". It's a cliche, but I think he was brillant. The book involves all sorts of creatures who are going to sleep, and creatures who do strange things in their sleep, sleepwalk, walking with hoops. There are even a couple of tongue twisters thrown in for good measure.
"The Runaway Bunny" by Margaret Wise Brown. In this story, the little bunny says he's going to run away, and his mother talks about how she'll chase after him. I'd like to think it's all about unconditional love, the love that I have for my two.