Born in Portland, Oregon; spent teen years in the San Fernando Valley; served 3 years in the US Army as a corpsman and surgical assistant at the 130th Station Hospital in Heidelberg, Germany, 1972-75; attended the University of Maryland extension, Portland State University, LA Pierce College, UCLA extension, California State University at Northridge. Teachers included Lucille Ball, Sidney Salkow (director of Last Man on Earth) and Ben Brady (producer of The Outer Limits). Freelance newspaper & magazine writing led to magazine editing jobs. With John Brancato, Newsom co-wrote "The Un-Official NFL Players Handbook," a humor book for Simon & Schuster. Brancato and Newsom collaborated on several screenplays of Marvel Comics characters, working with Stan Lee: Sgt. Fury, Spider-Man, and The Sub-Mariner. Active in the WGA strike in 1988, segued into directing and producing, concentrating primarily on video documentaries. He has served as associate producer on several CD releases of the film music of Ronald Stein , such as Not of This Earth (Varese Saraband), The Haunted Palace and Invasion of the Saucer Men (Percepto Records). Newsom is one of the partners of the Perma Production Music Library.

Newsom was the last director to team British horror stars Peter Cushing and Christopher Lee, in his documentary Flesh and Blood: The Hammer Heritage of Horror (1994) (TV), which the actors co-narrated.Wrote the original screenplay of Spider-Man with then-partner John Brancato (co-author of The Net and The Game), subsequently rewritten by Barney Cohen and polished by "Joseph Goldman" (aka Menahem Golan). A 1993 draft of this script also credits James Cameron. That draft is available on-line.Was the inspiration for the character of Eric Newsom in the short story "The Girl on the Cutting Room Floor" by Bob Statzer, originally published in "Scary Monsters Magazine" #75 (June 2010).