Sweet Bro and Hella Jeff is a webcomic, written by Andrew Hussie. It takes place in a webcomic called Homestuck, also written by Andrew Hussie, only inside of Homestuck, it isn't written by Andrew Hussie, but by an ultraironic young man named Dave Strider.
Sweet Bro and Hella Jeff was originally written as something of a throwaway joke by Hussie, as a satire on poorly done webcomics centered around gamer and "bro" lifestyle. Sweet Bro and Hella Jeff are poorly drawn, characterless characters who spend most of their time eating machos, watching sports and insulting each other. Or at least that is how the comic begins: it quickly becomes more and more absurd, with the already sketchily drawn Sweet Bro and Hella Jeff disintegrating into jpg artifacts. Inside of Homestuck, Sweet Bro and Hella Jeff is drawn by Dave Strider, one of the four friends that make up the game's opening core of protagonists. Dave Strider, at the age of 13, is already a seasoned satirist, who produces Sweet Bro and Hella Jeff to mock the "bro" culture, even though they don't know they are being mocked. In yet another iteration of the universe of Homestuck, Sweet Bro and Hella Jeff is a series of movies, each with a slightly different misspelling of the main title. These movies were seen as a coded act of heroic resistance to the tyranny of Betty Crocker, but I have now spiraled into the temptation of explaining the plot of Homestuck.
It is also possible that some of the events reported in surreal fashion in Sweet Bro and Hella Jeff are references or reinterpretations of events in the larger Homestuck universe, such as a surreal chess game ending in cheating. However, to fully address this issue would require a better explanation of Homestuck, which can not be explained in less time than it takes to read. The single most important plot point of Sweet Bro and Hella Jeff is brought up in the first comic, where Hella Jeff tumbles down a flight of stairs, and Sweet Bro admonishes him that "I told you about stairs, but it keeps happening", with both stairs, warnings, and the continuance of unfortunate events being a continued theme across Homestuck.
Sweet Bro and Hella Jeff can be read here: http://www.mspaintadventures.com/sweetbroandhellajeff/, which also gives information on the recent Sweet Bro and Hella Jeff limited edition book.