Eric Stoltz has signed to play John Brooke in the latest film adaptation of "Little Women." He says, laughing, that by joining the cast led by Winona Ryder, "I'm throwing my family a bone. At Christmastime, my sisters and my parents gave me grief that all of my films are rated R, so the children can't see them." The newest version of "Little Women" adheres fairly closely to the Louisa May Alcott original, says Stoltz - who does indeed have a heavy share of not-for-tykes fare on the way. Besides starring with Randy Quaid in the AIDS-themed NBC movie "Roommates," airing May 30, he's among the stars in Martin Scorsese's coming big-screen "Naked in New York." Eric also has his sophisticated romantic comedy "Sleep With Me" - which he produced - ready to bow at the Cannes Film Festival. Then there's Quentin Tarantino's "Pulp Fiction," also being launched at Cannes. "I play Lance the drug dealer," he cheerfully lets us know. "It's very gritty . . . guaranteed to have something in it to offend everyone."