Qui-Gon Jinn was discovered as a child to have great force potential and was made the padawan of Count Dooku. He quickly advanced and was made a Jedi Knight. Known for his temper, he caused a controversy when he accused another Jedi of committing adultery with some queen, and forcing the knight to engage in a duel to defend the queen's honor. Qui-Gon was severely injured in the duel and for a brief period was forced to wear bandages on his face. During this time he became a vigilante named Darkman.
Having severely damaged his reputation among the Jedi, Qui-Gon took over his family's factory ship and went to work producing medical rope and action figures. While attempting to profiteer a war between the Toydarians anf the Nimbanese. Seeing the way that the Toydarians were mistreating their Nimbanese prisoners of War, Qui-Gon spent his entire fortune purchasing the Nimbanese slaves and setting them free.
His honor restored, Qui-Gon rejoined the Jedi order and was about to be named to the council when he killed 130 people in order to rescue his kidnapped daughter. In a last ditch effort to prove what a valuable member of the order Jinn could be, Yoda sent him to the planet London to negotiate a peaceful resolution to the Irish Question. He was successful, to a point. He ended hundreds of years of fighting, but a piece of the land was kept while giving most of it back to the Irish.
Qui-Gon was named a Jedi Master, and took on Obi-Wan Kenobi as a padawan. Since the council wanted him to retire, they kept giving him boring assignments that involved very little killing, like negotiating trade disputes. During one such mission on Naboo, Qui-Gon and Obi-Wan ended up in an invasion, and joined up with Jar Jar Binks, a Gungan outcast. Naturally, Qui-Gon decided to drag the annoying fool around while searching for even more annoying people to surround himself with. While visiting Tatooine, he saw his chance and worked out a deal to bring along a kid who didn't understand how dialogue worked.
After further pissing off the council by demanding that the annoying kid be trained as a Jedi, Qui-Gon went back to Naboo and was slain by Darth Maul.
Qui-Gon had, at some point, figured out how to hang out as a ghost after he died. He mostly used this skill to taunt Yoda.
Qui-Gon was known as a practical joker and a master of improvisational comedy. He would make up elaborate stories on the spot, and pass them off as truth. His best known lie was that tiny creatures called midichlorians lived in peoples' blood and determined their force potential. Obi-Wan frequently played along with that one, and it became so widespread that many people actually believed it was true despite how ridiculously stupid it was.
Qui-Gon had one lightsaber, which was borrowed for a moment by Obi-Wan to take care of Darth Maul. It had a green blade, but Kenobi went and found his blue bladed one as he preferred that one.