If your students are interested in getting their writing published, they (and you) should check out the Young Authors Guide at New Pages. The guide includes magazines that are looking for student writing to publish as well as contests for student writers.
New Pages has amazing resources for all writers, including calls for submissions and magazine reviews.
Important note: You should not pay for a book by some publisher who has published your work. In particular you should never pay something like $24.95 for such a book. Publishers should give you something if they publish your work.