Read a variety of poems first. I would recommend a couple of different kinds of poems before assigning any writing activities. For more ideas on how to start a unit on poetry, be sure to take a look at Introducing and Reading Poetry with English Language Learners. While the introduction doesn't have to be too in-depth, giving students time to read and think about poems will help them feel more comfortable when it's time to write.
Introduce different poetry forms as models. Read some poems that fit the structure or format, discuss unique rhyming or line patterns, and then have students try writing on their own, using the poems read in class as a model. Focus on each form before moving on to the next one so that students have a chance to master it.
Use poetry throughout the curriculum. You may also wish to use poetry writing as an activity in other content-area lessons, or trying having students write some of these poems as riddles that their classmates have to figure out.
