What is the best book on writing poetry?

Question:(I'm sorry if this question has been asked a million times, I'm new here).

What is the a good book for learning about poetry in general, theories for why poetry is written, thoughts on techniques?

Best Answer - Chosen by Asker: (I'm sorry if this question has been asked a million times, I'm new here).

What is the a good book for learning about poetry in general, theories for why poetry is written, thoughts on techniques?

i loved "the poet's companion" i read it with an intro class...its quick reading (read in a few weeks) and it never got boring...it's cheap to :)...isbn is : 0-393-31654-8..u can get one on amazon for about $8