Shadow Poetry is a great poet's resource. They explain what poetry is, what the different types of poetry are, and have many poetry guide.
They outline the various types of poetry, including traditional poetry, types of Japanese poetry, and other more modern types of poetry.
They also have a poetry handbook/glossary, which is useful for finding different poetry terminology. They also have a very extensive poetry guide, which I highly recommend if you're serious about writing poetry.
ShadowPoetry.com - Types of Poetry Guide
An informational poetry resource outlining various types of poetry.