We are very excited as we are about to begin a study of the moon! I have put together lots of different materials. Earthsky.org has some excellent and simple explanations of the moons phases. They were probably some of the most concise and straightforward ones I have read. I printed out each of them and read them over to get an understanding. I then created a container story which I told to teach the topic during a lesson block on time.
I also came across this really neat simulation of the moon cycles. Once you know the different phases, you can actually follow the image, seeing (and recognizing) each of them.