Ask Gothamist recently saw Mean Girls and while it's a good movie on its own, it's easily the best movie we can think of based on a non-fiction book without any sort of actual story arc.
Surely the first film on anyone's list of the best movies based on bestselling advice books - a limited genre to be sure - is Woody Allen's comedy Everything You Always Wanted to Know About Sex * But Were Afraid to Ask. Released in 1972, the movie is a series of sketches that take their themes from chapters in the book by Dr. David Reuben.
The cast includes Allen, Tony Randall, Lynn Redgrave, Burt Reynolds, Gene Wilder and even Regis Philbin and Ask Gothamist remembers being very amused - but very confused - by the movie when we saw it as a kid. Here's some good advice: don't watch "Everything You Wanted to Know About Sex" if you don't know anything about sex. Those men in the little white suits are funny looking, but what are they doing with those big long tails?