Dana Goodyear's October 2008 profile in The New Yorker affords some insights. As does this 1999 interview/conversation with Peter Coyote for Poetry Flash. As does this video interview here and here, and this radio interview here, and this earlier (1991) audio interview, to cite just a few of the available sources.
1991, that would be just one year before the publication of "No Nature:New and Selected Poems", Snyder's first gathering of "Selected Poems". His reading from that book at the wonderful D.G.Wills bookstore in San Diego has been, fortunately, captured for posterity and can be viewed here.
Another, more recent, celebration was the UC Berkeley 2009 50th anniversary of "Riprap" (Robert Hass generously introduces him - the tape also includes memorable appearances by Cecil Giscombe and Lyn Hejinian - Gary speaks, reads, and comes back later, at the end of the evening, to read a little of his translations of Han Shan)
A solo reading at that same venue earlier that year (as part of the estimable Lunch Poems: Noontime Poetry Reading Series) is also on-line/available and can be viewed here.
This 2007 Czech tv profile is also illuminating.
November 24 1958, all of 28!. More audio from Gary can be heard on this French site, La Voix de Gary Snyder, and, then, not forgetting (and let's not forget) the extraordinary resources of the NAROPA Archives (among their highlights, this August 12 1983 reading (Gary's an old man at this point, he's 53! - and this, from 1990, Joanne Kyger('s) class on Gary Snyder's work. To quote the NAROPA catalog note: "She discusses his life, his interest in Zen and the journals included in "Earth House Hold". Part way through the class, Snyder appears in person. He and Kyger discuss mythology and literature. Snyder then reads and discusses his work (and) Kyger reads some of her own poetry"
Gary Snyder's "Writers And The War Against Nature", a powerful autobiographical essay has been published by Shambhala Sun.
Click here for the Smokey the Bear Sutra.
Then there's the phenomenon of the recent film, "The Practice of the Wild: A Conversation with Gary Snyder and Jim Harrison". Here's three recent reviews of it - here, here, and here.
and Jim Lenfestey's memoir/preview for Gary's April 18 (2011) Minneapolis performance (not to mention Chris Welsch's interview in the Star Tribune)
and not forgetting the Ginsberg/Snyder letters
and here's a site with twenty Snyder poems.