Here are a few of my favorites:
Giggle Poetry is a site full of fun poems for kids. They can even rate the poems on a "Giggle Meter" after reading them.
And here's one just of Haikus
Karen Barry of KB...Konnected has created this livebinder FULL of poetry links, lessons, and resources. I highly recommend bookmarking this one.
And I LOVE this Poem in Your Pocket Day freebie from Karen Barry of KB...Konnected. You can find it here on TpT.
What resources do you use for National Poetry Month?