The Japanese Language Proficiency Test is the most well-known test of Japanese proficiency for non-native speakers. There are five test levels (N5, the lowest, to N1, the highest). Once students have a basic understanding of Japanese, it can be very rewarding for them to take a test like this to prove their level of proficiency.
Kanji are inherently interesting and the Kanji Proficiency Test is a good way to motivate students to learn the characters. This test is designed for native speakers of Japanese, but the workbooks can be used to teach non-native speakers. Link: Books on Amazon.co.jp
Japanese embassies around the world often have useful resources on their websites. They also have maps, brochures, posters, and pamphlets that can be used in the classroom. It is a good idea to make contact with the embassy or consulate closest to you in order to be kept aware of the resources that they have
One of the goals of the Japan Foundation is to promote Japanese language and culture throughout the world. They have many useful resources on their website. Link: http://www.jpf.go.jp/e/japanese/resource/index.html