(written from a Production point of view)
Margaret Clark is an editor and writer. Most recently working for Pocket Books, Clark has worked for DC Comics and Marvel Comics in the past, both as a writer and editor. Many of her projects for Pocket Books and DC Comics concerned Star Trek-related titles.
While in the comics industry at Marvel Comics, Clark did not work on any Star Trek projects during her employment there, as that company only started to release Star Trek-related titles again in 1996, after their early 1979-1981 releases. One of her last big project at Marvel however, was to serve as the supervising editor of project editors Jean-Marc and Randy Lofficier, who were tasked with publishing the then body of work of renowned French comic artist Jean "Moebius" Giraud for the US market. Clark was involved in the decision to have the work not released in the standard US comic book format, but rather in the more posh European derived graphic novel paperback format, a relatively new phenomenon in the US comic market at that point in time. (Comics Scene, issue 9, 1989, p. 9) Clark though, left the company before that prestigious project was completed. Moebius incidentally, was admired by Michael Okuda, as a Moebius art piece was prominently displayed on the walls of his work station in his Star Trek art department. 
After having moved over to DC Comics, Clark served primarily as an editor from mid-1989 until 1996, but also wrote issues of "Critical Mass", "Doctor Zero", "St. George", and co-wrote "The Punisher/Captain America: Blood and Glory" in 1992, the latter for her former employer Marvel incidentally. Clark became professionally acquainted with Star Trek in that era when she edited DC's Original Series comics (editing all of the issues from #59: "No Compromise Part Two" through #80: "The Chosen Part 3: Collision Course!") and Next Generation comics (editing every issue from #56: "Companionship" through to #80: "The Abandoned"), plus the Star Trek: The Next Generation - Ill Wind mini-series written by Diane Duane. Clark also brought Rachel Ketchum onto the TOS line as the primary pencil artist during her time as editor.
Clark joined Pocket Books as an editor in 1995. Working on a number of different licenses, she was initially responsible for the Star Trek line's reference works, her role expanding into editing the fiction lines in 2002 with the Star Trek: Enterprise series, and later with Next Generation novels set after Star Trek Nemesis. A project she herself conceived concerned the coffee-table format reference book Star Trek: Action! (1998), which became a commercial flop however. And indeed, where the reference works were concerned, Author and Production Illutrator Rick Sternbach has expressed his doubts about Clark's editorial qualities, especially in regard to the by him co-authored Star Trek: Deep Space Nine Technical Manual, as he deemed her text editing had "dumbed down the tech nature of the book". Previously, Sternbach had already stated, "I'm not inclined at the time to work with them, due in part to the editorial differences of opinion I had with them over the 1701-D blueprints and DS9 TM." 
Following the departure of senior editor Marco Palmieri in December 2008, Clark took over principal responsibility for Pocket's Star Trek line. However, as a result of further downsizing by Pocket parent company Simon & Schuster – or rather the restructuring of the entire Star Trek franchise by its parent company CBS Corporation – , Clark herself was let go in August 2009 , although she was retained as a freelancer later on, continuing to work on the popular Star Trek: Ships of the Line calendars (already launched under her auspices in 2001), among other projects. Clark became alienated with two original conceptual authors of the calendar series, Adam Lebowitz and Robert Bonchune, both of whom she replaced in 2003 with Doug Drexler as chief editor after the first three outings in the series. With Drexler, Clark has developed a warm working relationship, conceiving with him the book derivative of the calendars.