SIXTY-FIVE YEARS ago today, some sidewalk-sitting kids began to hate Charlie Brown.

It was the debut strip of “Peanuts,” in just nine newspapers, but gradually, of course, the world began to love Charlie Brown.

And this little United Feature Syndicate comic, drawn by the humble son of a Minnesota barber, would grow to become not only one of the most beloved comic strips ever, but also one of the most influential.

“There’s ‘Peanuts,’ and there’s everything that came after it,” bestselling author Jeff Kinney (“Diary of a Wimpy Kid”) writes in the introduction to a beautiful new book, “Only What’s Necessary: Charles M. Schulz and the Art of Peanuts” (Abrams ComicArts; due out Oct. 20). “Virtually every successful comic strip feature that has followed ‘Peanuts’ owes a huge debt of gratitude to Schulz for getting to the very essence of what makes comics a powerful medium.”

As we celebrate the legendary strip’s 65th anniversary today, there are so many fresh means to appreciate “Peanuts” anew.

“Only What’s Necessary,” edited and designed by Chip Kidd (who delves once more into the rich “Peanuts” archives, 15 years after his “Peanuts: The Art of Charles M. Schulz” book), derives its apt title from “Sparky” Schulz’s genius for delivering emotionally complex characters in the form of visual simplicity. As Kinney writes:

“Less space meant making every line count. Every word of dialogue. Every gesture.
“By using only what was necessary in his own strip, Schulz transformed people’s understanding of what comics could be. In a time when the comics page was crowded with densely drawn, dialogue-heavy creations, Schulz’s work was a beacon of simplicity and economy.”

The coffee table-sized book (with photography by Geoff Spear) is treasury as trove. It opens with a wealth of well-considered insights, from Kinney’s intro to a “behind the doors” appreciation from Karen Johnson, museum director at the Charles M. Schulz Museum and Research Center. (“It is appropriate that this book comes out on the sixty-fifth anniversary of ‘Peanuts,’ ” Johnson writes, “a year filled with celebration, reflection, scholarship, and ultimately, confirmation that ‘Peanuts’ is truly art.” There is Kidd’s preface, which sets the stage for enjoying this hard-bound spotlight on Schulz’s “singular achievements.”

But the words that informed me the most were those of Jean Schulz, the cartoonist’s widow. I’ve been blessed to communicate regularly with Jeannie over the past decade and a half about all things “Peanuts” — not long after I met the “Sparky” himself. Yet here, in her foreword, are lucid and highly illuminating insights that we’ve never had a chance to touch upon.

Take, for example, how Schulz rendered rain. Will Eisner might be his only contemporary who could knock your (wet) soaks off with how he pictured precipitation. Schulz might devote 100 deft lines to dynamic raindrops in a single panel. “I know for Sparky,” his widow writes, “it was a thrilling exercise.” (And the foreword acknowledges, too, the vital role of “Peanuts” studios creative director Paige Braddock.)

And fittingly, you could spend a warm, rainy afternoon completely immersed in this “Peanuts” art book, as rapt as if it were a large-format security blanket. You can bask in the pencil sketches and little-seen watercolors, and begin to get a sense of just how much Schulz’s originals have a “3-D effect,” as the ink sits up on the Bristol board. And readers new to some of the backstories can learn about how Franklin not only integrated a comic strip, but stirred controversy and inspired numerous readers during the civil-rights era. And there, in full color, is the final Peanuts” strip, which ran on Sunday, Feb. 13, 2000 — the day after Schulz died at his Santa Rosa home.

Also this week, “Peanuts” fans have begun to celebrate the feature through postage (putting the “lately” in “philately”).  The U.S. Postal Service has just begun issuing “Charlie Brown Christmas” stamps to mark the 50th anniversary of the Emmy-winning special.

Then there’s another forthcoming book, “Snoopy vs. the Red Baron” (due in November from Fantagraphics), which collects especially memorable strips featuring the rich fantasies of Snoopy, the root beer-quaffing fighter pilot.

And then, of course, there’s the feature film due out Nov. 6. I’ve screened nearly 25 minutes of the film, and spent a day at Blue Sky Studios with creative talents behind the project, so I’m highly optimistic that the public will embrace “The Peanuts Movie.” Because for all its rich animation, which blends digital effects with Schulz’s true line (including his own 2-D renderings of rain), the filmmakers seem focused on only what’s necessary.

As Schulz himself wrote in his final “Peanuts” strip, a half-century after his genius found beguilingly simplistic life on the comics page: “Charlie Brown, Snoopy, Linus, Lucy … how can I ever forget them … ”