Excelsior!
Stanley Martin Lieber, a.k.a. Stan Lee, loved the written word from an early age, and wanted to craft stories like those in his favorite books and films, which he consumed voraciously. From a simple upbringing in the teeming landscape of Manhattan, young Stanley worked his way through a succession of jobs until the day he found himself an assistant at a comic book publishing company — Timely Comics.
In between refilling artists' inkwells, erasing pencil lines from comic pages and fetching an untold number of lunches, Stanley expressed his desire to write and create tales of his own; in the May 1941 issue of CAPTAIN AMERICA COMICS #3, he got his wish. Readers would find a prose story in that issue, "Captain America Foils the Traitor's Revenge," sporting the byline of "Stan Lee." A star was born.
As Stan's roles and tenure with Timely Comics grew and evolved, so did the company itself. With Stan at its helm, Timely Comics morphed first into Atlas Comics and then into the name that would catapult it into legend and forever be synonymous with Stan Lee: Marvel Comics.
As Marvel's Editor-in-Chief, Stan "The Man" Lee made his voice the voice of the stories themselves. Writing virtually every Marvel title and working with such luminaries as Jack Kirby and Steve Ditko, Stan began building a universe of interlocking continuity, one where fans felt as if they could turn a street corner and run into a Super Hero. A rich collection of characters grew out of his nonstop plotting sessions with his artists, including the Fantastic Four, Spider-Man, Thor, Iron Man, the Hulk, the X-Men, and more.
In later years, Stan took on new projects of his own outside of Marvel, but always kept one eye on the universe he created, watching with pride as it continued to grow and expand. Stan worked tirelessly to promote Marvel properties and characters to the film industry, and his spunky cameos in Marvel films and television series became an important part of his legacy.
Here's a video with every Stan Lee Cameo.
If you have time, you should read more about Stan Lee on his Wikipedia Entry.