Two books about poetry that I highly recommend are:
1) The Eye of the Poet; Six Views of the Art and Craft of Poetry, edited by David Citino (Oxford University Press, 2002). The book is written by practicing poets and teachers of poetry. The poets represented are David Baker, David Citino, Billy Collins, Yusef Komunyakaa, Maxine Kumin, Carol Muske, and Ann Townsend. That's seven, if you're counting. David Baker and Ann Townsend co-write a chapter. Each essay offers a different slant on writing and reading poetry.
2) The Poetry Home Repair Manual, by Ted Kooser (University of Nebraska Press, 2005).
Ted Kooser was the 13th Poet Laureate Consultant in Poetry to the Library of Congress.
The title provides a clue to Mr. Kooser's approach. He gives practical advice in plain language.
I particularly like the chapters on writing about feelings and writing from memory.
Both are books to which I return from time to time, always finding new insights.