My very favorite hands-down poetry resource is Suzanne Rhodes’ The Roar on the Other Side. I’d really only recommend it for junior high and up. I don’t really teach much form or ANY poetry writing to little kids since nearly everything is centered around twaddly forms like haiku or acrostics. (Haiku is not bad–in Japanese. However, nearly every haiku written in English by American school kids forced to write “poetry” is undadulterated twaddle.) What I especially like about The Roar on the Other Side is that it doesn’t just teach mindless form but how to SEE what you want to write about and how to choose a form that would fit it. he begins with observation, not sonnet rules. LOL If a student, having finished Roar, is still interested in metrical poetry, then Rules for the Dance by Mary Oliver, one of the best contemporary poets, is the thing you need.