Teaching children about the stars can be fun for both the instructor and the students, but getting a group to a full-scale planetarium can be a challenge. How about building your own instead?
You can construct a simple planetarium from cardboard, and the methods are basic enough that your students can be involved in the project. Depending how permanent you intend your structure to be, you can easily break it down and reassemble it.
You will have to read the article for the directions on how to build the Planetarium. Not only will you be able to build your planetarium but you will also learn some basic geometry which is cool to learn at any age.