NASA has always had great educational resources. The new Rocketry site is another example.
The site is meant to help get students excited about rockets and science in general. There are a huge number of resources, from information about careers in rocketry, to how to build a rocket, and more. There are links to information about NASA missions, rockets and vehicles, and related topics. There are lesson plans, images, multimedia, games and simulations. There are even links to web casts that NASA produces for students and teachers.
This is not just for science teachers. Math, History, and even English can use lesson about rockets in their classrooms.