Where do you start when you're making a documentary about a Hollywood legend like Jerry Lewis? Director-producer Gregg Barson, a lifelong Lewis fan, first met the comic in 2004 while he was working on a project about the life of Phyllis Diller when he struck up a friendship with the comedian and came up with the idea to make documentary about his storied career.

That was nearly eight years ago and now, as Encore prepares to air Method to the Madness of Jerry Lewis -- a feature-length documentary set to premiere Saturday at 8 p.m. -- Barson tells The Hollywood Reporter five things to know about the production.

1. Barson interviewed scores of Hollywood A-listers for the two-hour project, including Jerry Seinfeld, Billy Crystal, Quentin Tarantino, Eddie Murphy, Carol Burnett, Steven Spielberg and Alec Baldwin, among others, with each offering a different take on Lewis. "Tarantino was impacted by his filmmaking, the same with John Landis," Barson says. "Seinfeld was the most scholarly with his description of the artform of comedy and what Jerry did and Billy was more emotional." Lewis' longtime friend Richard Belzer, meanwhile, put everything into perspective and what Lewish meant to comedy and showbiz. "Most of the interviewees we'd just keep shooting -- once we started taking about Jerry, it brought them back to their childhood and their memories of him," Barson notes. "They just light up when they talk about him."

2. There's a little of Jerry Lewis in everyone. The general consensus is that of today's comics, the ones who come closest to Lewis are Jim Carrey, Robin Williams and Billy Crystal, but you'd be hard-pressed to find a comic who doesn't have traces of the legend. "Everyone has a bit of Jerry in them because he became co ingrained in comedy," Barson says. "He's in every comic because it's all been derivative -- he's a cornerstone of comedy."

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3. Lewis' legacy. On the set, Barson says Lewis would typically refer to his characters as "The Kid" or "The Idiot" but will leave a legacy that goes far beyond the iconic on-screen personas. "He wasn't just that kid or the idiot, he was an inventor and a real director who broke ground and was a creative genius," he says. "For him I think that word is acceptable: he wrote his films, directed, produced and acted in them and he invented the video assist. His legacy is peppered throughout showbiz and not just comedy -- but also in the technical end of filmmaking."

4. Method was three and a half years in the making. "When I first pitched this in 2004, Jerry said it has to be about chemistry," Barson recalls, noting Lewis was very candid during production, often inventing new routines for the crew. "You could tell he was enjoying the process; he's the same when the camera is on and off and there aren't many people like that."

5. Lewis was very hands on, often turning into mentor of sorts for Barson. "There were points where I'd be shooting him and he'd say to get a shot from a different location," he recalls. ""I thought, 'Jerry Lewis is helping me direct and giving me pointers." During the process, Lewis screen cuts of Method and offer notes on the craft, cutting, timing and pacing. After screening the completed doc, Lewis had no notes -- but his son, however, did have one. "His son once said we should call it Jerry Lewis Eats," Barson says with a laugh, recalling the many restaurants the crew filmed in.  

Method to the Madness of Jerry Lewis premieres Saturday, Dec. 17 at 8 p.m. on Encore. The network will dedicate much of Saturday afternoon's programming to a Jerry Lewis marathon, broadcasting films including The Bellboy starting at 1:50 p.m.

Check out a gallery of rarely seen vintage photos from Lewis' storied career here.

Email: Lesley.Goldberg@thr.com; Twitter: @Snoodit