For practicing poets this work hardly needs an introduction--earlier editions have become dog-eared with use; the handbook is indispensible and time-tested.
For beginners, Turco's Book of Forms will become your best companion, your most useful and valued discovery, always at hand to answer your questions on form and the workings of language in poetry. No question you have is dumb. Your wilderness isn't trackless any more--Turco has been there and helps you take the direction you want. The book is supportive and informative in tone as well as in factual information.
When the first edition came out in 1968, I was taking a poetry workshop where one of the workshop leaders mentioned this new handbook ... a tad different from the Deutsch and perhaps others? we'd seen. Turco's Book of Forms delighted me by including, not just the familiar information on sonnets, triolets, and villanelles ... it talked of forms I'd never encountered--Welsh and Irish forms-- that opened whole new worlds of possibilities in writing. But there was one lack in that earliest edition-- there were no poem-examples, only schematics.
Later editions remedied that lack; and this fourth edition goes even further, being at the cutting edge of creation where ideas are born, illustrating forms writers are in the very act of creating right now. It makes exciting reading.