This book isn't worth the money unless you absolutely must have everything Kerouac ever wrote. It's only got about 40 pages of poems, and if that's not bad enough, most all of the poems are published in other books.
"San Francisco Blues: Two Choruses," "Orizaba Blues: Four Choruses," and "Orlando Blues: 31st Chorus" can all be found in their entirety in Book of Blues, which is highly recommended if only because it contains the excellent "San Francisco Blues." "MacDougal Street Blues" and "My Gang" are in the wonderful & inconsistent collection Pomes All Sizes. The "Poems for Don Allen's Anthology" are choruses from "Mexico City Blues," chosen for Don Allen's anthology by Allen Ginsberg. The 20 pages of letters by Kerouac to Don Allen, while interesting, presumably can be found in Kerouac's Collected Letters. The letters also contain a "Biographical Resume" and "Biography" written by Kerouac (included in other books, I think--Good Blonde?), his statement on poetics and poetry found in Don Allen's anthology, and "Belief & Technique for Modern Prose: List of Essentials" found in the Beat Reader and Good Blonde.
So, what does that leave? Not much. The only things I'm pretty sure can't be found anywhere else are the 1958 poems "A TV Poem" and "Heaven," totaling 10 pages, as well as a one-page cartoon entitled "Doctor Sax and the Deception of the Sea Shroud" drawn at Neal Cassady's house circa 1953-54. And the two poems aren't even that good. However, "Heaven" is very interesting in that it marks a clear shift between Kerouac's Buddhist period and his later alcoholic Catholicism, and it gives us insight into Kerouac's Christian beliefs. A couple interesting quotes from "Heaven":
"The Church? Earth's dogmatic mistakes have nothing to do with Heaven"
"For we all go back where we came from, God's Lit Brain, his transcendent Eye of Wisdom / And there's your bloody circle called samsara by the ignorant Buddhists, who will still be funny Masters up there, bless em."
Oh, so now the Buddhists are ignorant? and this was written just a year or two after The Dharma Bums, wow.
So anyways, this book has a good deal of interesting stuff -- poems, letters, autobiographies, statements -- but most of it can be found elsewhere. If you don't have Book of Blues, Mexico City Blues, and Pomes All Sizes yet, don't bother with this book. But if you gotta have it all, then by all means get it.