(Note: Many of these sites may be directed to teaching poetry terms to younger children and may have to be adapted for your use.)
Sources for Ideas/Lesson Plans:
Poetry Class - Poetry Lessons
"Poetic News Activity" - from the Teaching Poetry web site
PoetryTeacher.com - Lesson Plans
ProTeacher.com - some neat ideas for teaching metaphors, alliteration, etc.
Wikipedia Encyclopedia Entry on Poetry - definitions of terms and examples
Teaching Ideas Showcase - dozens of ideas for teaching poetry
Sources for Poems:
Internet Poetry Archive - modern poets
Poetry Archives - thousands of classical poems
"Our Poem Collections" from about.com