Don't detour around this one!
The title alone gives you a taste of Stephen Fry's entertaining writing style. In a humorous, extremely well-written book he explains poetic meter, rhyme and the rules for a number of set forms of poetry. Each step of the way, he encourages the reader to STOP and put into practice what he has just learned. He even touches on the history of poetry--who would have thought the subject could be so interesting! Would I recommend this book? I already have: to my writers group, to several fellow poets, and to you. An entire poetry course in one volume. I came away from it entertained, informed, and with several publishable poems. I can't wait to read it again, and again, and again.
My only caution is the language is a bit coarse in a few areas (especially the limerick section), but don't avoid the book just because of that.