Elevated to mythical status by Boba Fett, Mandos have always been the quintessential Badasses. Whether it's taking out a senator, blockading the Jedi temple or fighting a war for the glory of their people in the Great War, they've always been the family-oriented, bounty hunting, strange-language speaking warriors in awesome armor.
They originally started out as a humanoid species called the Taung, 200,000 years before the first death star blew up. They got in a war with the 13 human tribes of coruscant. So they left to the outer rim, conquered a planet, started living on it, and became a warrior culture. Also, they started doing it with humans until they became humans, with slightly denser muscle tissue, and a mental condition called "triggerable psychosis", where they can focus all of their mental power to ending a fight, literally becoming a ball of rage. They choose a leader through a few different ways, either gladiator-style fighting, elections, war heroes or espionage. These they call Mandalores.
Mandalore the Ultimate and Cassus Fett
In about 40 ABY, Boba Fett became the Mandalore, but there was a microbe in the air preventing him from even setting foot on Mandalore again or he'd die. So that sucks. In 45 ABY, the Mandos were hired by Admiral Natasi Dalaa, the head of the GA, to assault the Jedi temple and retrieve some prisoners. They failed because the authors of that series are a bunch of faggots with no respect for the mandos. And to top it off, they blockaded the Jedi temple and killed a sweet, innocent Jedi girl. Poor, poor girl. Nevermind the fact she could have killed them instantly with her mind. But she was wearing a skirt, so it was totally cold-blooded.
There are a bunch of Mando fan club and cosplay sites, such as Mandalorian Mercs, The Dented Helmet and the 501st Legion. They make their own armor and helmets, weapons and stuff, and be all cool and stuff. It's pretty awesome. Heres some dresser uppers.
In conclusion, Mandos rock, you don't if you don't like em.