Websites
This is the main center for all things Blake. Check it out.
The poetry foundation is an excellent resource for other poems by Blake—giving a decent sampling of some of the most popular.
This excellent resource has all of Blake's poems and a ton of his famous paintings and engravings.
Audio
Here's a solid recording of Blake's great poem, read by an actor.
This is another version, read by Ted Hughes, a famous British poet (who was also famous for being married to Sylvia Plath).
This isn't the same as Blake's poem—but it's inspired by it and it has the same title. Patti Smith—"The Godmother of Punk"—was a big fan of Blake, along with so many other rockers.
This is one of Dylan's most religious songs—and it's deeply influenced by Blake, and "Auguries" in particular. Emmylou Harris delivers a version that's a little easier on the ears than the original.
Images
This was painted from Blake in life. It brings out his intensity, and gives the impression of a mind that's focused, but is also looking at something beyond the everyday world.
This painting got a lot of play in the movie Red Dragon (and in the book it's based on), where it's tattooed on the back of a serial killer (who also destroys the original painting at one point in the story). It's a good example of Blake's spiritual art, since it's based off a scene from the Biblical Book of Revelation.
This Blake painting shows the figure "Albion" (an old term for Britain), who represents Blake's idea of the Cosmic Human or "Human Form Divine"—the God who appears in "realms of day" at the end of "Auguries."
Articles and Interviews
This gives a very in-depth look at Blake's life.
Eliot's essay helped people take Blake seriously instead of just dismissing him as a madman. But Eliot's also a little critical—he doesn't like it that Blake invented his own mythology and wishes he'd used the orthodox Christian view of reality like Dante did.
Yeats adored Blake, and his essay is a lot more praiseful than Eliot's. He hails Blake for preaching a mystical "religion of art."
Books
Although the famous British author G.K. Chesterton had his own biases and quirks, he clearly loved Blake. He gives his individual and idiosyncratic take on the poet, which is definitely worth a look.
Swinburne was a major poet in his day, though he's not very frequently discussed anymore. But he was also an important literary critic. This book might be a little out-of-date, but hey—it's free. Swinburne's Blake book was totally a pioneering work in its day, since most people had just dismissed Blake as a lunatic during his lifetime.