Siddur Kol Hano'ar uses a truncated version of the Aleynu prayer. This fuller version uses Reconstructionist wording and can be pasted into siddur Kol Hano'ar. It is available with and without transliteration.
This annotated list includes many web links and one book about Tu B'Shevat for children and adults. It offers background information, history, stories, activities, seder readings and more.