Nashville-born Witherspoon has a long list of film credits, including The Man in the Moon, Jack the Bear, and Twilight, which starred Paul Newman and Susan Sarandon.
It's really wonderful as a young actor to get to learn from people and really experience people's knowledge," Witherspoon, now an English literature major at Stanford University, told CBS This Morning.
Maguire, born and reared in Santa Monica, began his career at age eight when he appeared in potato chip commercials. By 17, he had his own sitcom, Great Scott, that ran for six episodes on the Fox network.
He claims the "acting bug" is in his genes and once told an interviewer than his mother, a would-be actress, once offered him $100 to take drama classes instead of home economics in school.
Maguire has made guest appearances on a number of TV shows, including Walker, Texas Ranger, Roseanne, and Blossom. His film credits include This Boy's Life, Deconstructing Harry, The Ice Storm, and Fear and Loathing in Las Vegas.
Working with Woody Allen on Deconstructing Harry, Maguire said, was "really intimidating.
"I thought I was going to be really cool, but then I went and met him for the first audition, and I completely fell to pieces,"he said.
Witherspoon and Maguire are paired together in the new Gary Ross film, Pleasantville, that opens Oct. 23. They play a brother and sister who are suddenly transported from their 1990s world to a 1950s TV home, where their parents look and act like June and Ward Cleaver.
"We start disrupting their world, or Reese does, and I try to contain it," says Maguire. "Things go kind of crazy and lots of things happen."
The New Line Cinema film also stars Jeff Daniels, Joan Allen, and William Macy.