The Siegel and Shuster story is quite sad. Depression era kids looking to make a career when there wasn't many options. Jerry Siegel (the writer) and Joe Shuster (the artist) were known in their school where Siegel wrote for the paper and Shuster occasionally illustrated.
Though destined to be a big hit, Superman took years, and several re-takes to sell. The big money in that era was reserved for newspaper strips. Comic books were literally just starting out, with the first ones being re-prints of newspaper strips. Action Comics was a big risk with new characters and stories in a magazine format. Superman graced the cover of #1 and it sold very well.
Jerry and Joe were hired to keep this strip going while the iron was hot. They received $130 for the character and were hired to write and illustrate the comics. Though happy to get their creation into print, they were much happier to be employed doing what they liked and getting paid. National (as DC was known then) treated them reasonably well, but it became clear to Jerry and Joe that there was much bigger money on the table then they were making.
What follows is a story with several starts and stops, "winning" and getting some additonal $, but failing to get back their character. Superman kept growing - a 2nd monthly comic (Superman) which was unique in only having a single character, daily strip (the dream - Siegel and Shuster worked on this), Radio series and later a series of high quality cartoons (Fleischer), movie serials and a TV show and eventually a series of movies. Their character kept making astronomically more money than they figured at each point than they had bargained for - their share dwindling.
Joe Shuster was even homeless for a period of time, taken to a diner by a policeman and proving who he was by scribbling out a Superman onto a napkin.
When the Superman appeared on Broadway, Siegel and Shuster couldn't afford tickets.
Late in life they did reach a settlement which removed them from poverty, though they weren't the ones to get the riches Superman provided.
All in all a very good telling of a story that needs to be understood. Jack Kirby, who is probably best known for creating (or co-creating) a huge list of famous characters including: Captain America, Fantastic Four, The Incredible Hulk and Thor for a fledgling Marvel Comics. He too, was underappreciated for most of his life, and was even unable to recover the artwork he created for Marvel. He died relatively unhappy and underappreciated and likely jealous of Stan Lee who was credited with more than he deserved from the Marvel bonanza (though it is debatable whether he "took" credit wrongfully, or was "given" credit and didn't properly correct - Stan Lee has done a lot in the promotion of the characters, and it is difficult to see the actuality through the mist of the celebrity sometimes).