He is noted for biographies on Steve McQueen, Elvis Presley, Johnny Cash, Billy Graham and Pete Maravich.

An Air Force brat, he lived in Big Spring and Waco, Texas; Sacramento, California and Montgomery, Alabama.

Terrill moved back to Phoenix in 1994 and followed his biography on McQueen with collaborations with actor Edd "Kookie" Byrnes and actress Barbara Leigh, boxers Aaron Pryor, Ken Norton, and Earnie Shavers (co-authored with Mike Fitzgerald), and basketball legend David Thompson (co-authored by Sean Stormes).

London-based Plexus publishing updated Steve McQueen: Portrait of an American Rebel, with a new beginning and end chapter.

In October 2006, Terrill released Maravich, co-authored by Wayne Federman, an exhaustively researched biography on the basketball great, who died on January 5, 1988, from a heart defect.

The book is available as a free download by visiting http://www.asu.edu/firstfive/ebook.pdf The Arizona Republic named Terrill 'Biographer of the Year' in its annual best of issue in March 2012.

2014 saw the publication of two books: "Guitar With Wings" (Dalton Watson Fine Books), a photo memoir with Grammy Artist Laurence Juber, former guitarist for Paul McCartney's Wings (1978-1981) and "Zora Folley: The Distinguished Life and Mysterious Death of a Gentleman Boxer," a 93-page ebook.

The book also spawned a feature documentary called "Steve McQueen: American Icon" in which Terrill served as an executive producer.

Terrill and Laurie partnered again in 2019 for "Johnny Cash: The Redemption of an American Icon," continuing on with the series of examinations of pop culture artists who have become born again Christians.

In 2021, Terrill and Greg Laurie teamed up again for "Billy Graham: The Man I Knew," an intimate look at the world's best-known evangelist who was loved and known by millions.

Early in 2022, Terrill announced the formation of True Tales of the Southwest LLC, a production company dedicated to the creation of feature documentary films.