The website Venture Galleries has put together "Ray Bradbury's Primer for Writers", a neat summing up of typical advice Bradbury gives to would-be authors, based on his life's experience and achievements. There's not much here that's new, and most of the points can be found in Bradbury's book Zen and the Art of Writing and in the many interviews Bradbury has given over the years. Nevertheless, this is a neat encapsulation of the best points.Or, you could read an almost identical encapsulation here!
Snoopy's Guide to the Writing Life is slightly different: famous writers are asked to respond to a Snoopy Cartoon. You can read more about the book - and Ray Bradbury's contribution to it - here.