The book is called The Martian Chronicles. Its introduction is the short-short story, "Rocket Summer," dated (for the book) January 1999. It's now June 2012, and I'm still waiting for Rocket Summer, though Elon Musk's SpaceX (on which I posted recently) offer us belated encouragement. But I digress.
I discovered Bradbury through The Martian Chronicles. It's not so much a story as it is a collection of short stories from the 1940s and published in both mainstream and sf magazines (with all due respect to Forrest J. Ackerman, "science fiction" ought not be shortened "sci-fi") that Bradbury wove together and published as a book in 1950. Old Time Radio would re-broadcast the 1950s NBC Radio programs Dimension X and X Minus One, which included adaptions of several of these stories. The stories were magic when I discovered them as a young teen, and they remain magic when I return to them in my "advanced youth." (In the 1979-80 TV miniseries starring Rock Hudson, the magic is excised -- so don't bother.)
There's much, much more, of course. I'll leave that to the obituary writers, pointing you to this page from the Los Angeles Times where you can see an important side of Bradbury that others may not notice, but with which I connect.
And from the front page today of raybradbury.com:
...In 2005, Bradbury published a book of essays titled Bradbury Speaks, in which he wrote: In my later years I have looked in the mirror each day and found a happy person staring back. Occasionally I wonder why I can be so happy. The answer is that every day of my life I've worked only for myself and for the joy that comes from writing and creating. The image in my mirror is not optimistic, but the result of optimal behavior....And here are my other Ray Bradbury posts.
Throughout his life, Bradbury liked to recount the story of meeting a carnival magician, Mr. Electrico, in 1932. At the end of his performance Electrico reached out to the twelve-year-old Bradbury, touched the boy with his sword, and commanded, Live forever! Bradbury later said, I decided that was the greatest idea I had ever heard. I started writing every day. I never stopped.