Tell the Truth but Tell it Slant

My literature class is the unique challenge of this semester. I've never really taught anything like this before. The book we have isn't bad, it's got a good cross section of American writers, but it tries to cover too much for students who have no real foundation in the subject. I've been spending a lot of time going over literary terms like alliteration or metaphor since it's pretty hard to discuss much without them. Moreover though the real problem is that the student's really aren't used to thinking critically, and I don't want to just stand up there and try to beat into them what I think the poems or prose mean. I decided to start with poetry since it's short so we can talk about a whole poem rather quickly instead of one of these random chapters the book has taken out from famous novels. I can teach them what an allusion is, I'm just not sure I can teach them how to critically analyze anything.