Well unfortunately, all I know of Mandalorians comes from Knights of the Old Republic. In it (and I'm presuming the rest of the EU) Mandalorians are a warrior type alien race that are very similar to humans. ie they're bipedal, roughly the same height, have hair and two eyes, etc. In the game, the one Mandalorian you team up with can regenerate. I'm not sure if this is true of all of them, or just him. They're a very proud race and war for the challenge and glory of it, rather than bloodlust and plunder. At least, that's what Canderous (the guy you team up with) tells you. By the time of the game, (about 4000 years before A New Hope,) some Mandalorians have basically become scavengers, bandits and cutthroats. Canderous doesn't think highly of them. That's all I can think of, hope it helps :D

Originally, the Mandalorians were a proud warrior tribe of an ancient species called the Taung, which were driven from their native Coruscant by some of the first humans. Mandalorians eventually adopted humans into their clans and taught them the ways of the Mandalorian supercommandos. By the time of the 'Tales of the Jedi' period (4000 years before the Battle of Yavin), the Taungs have died out, but the human descendants of the adopted Mandalorians continue the tradition. Basicallly, 'Mandalorian' is an exclusive warrior tradition, native to an area of space where several Mandalorian-conquered planets are. Mandalorians are almost entirely human, though later they did start adopting other species who were committed to their code. Mandalorians can be either male or female--it's just that the female Mandalorians usually had more important things to do than go out and look for trouble. Mandalorians take family and children very very seriously, and have a strong tradition of adopting strangers with "the proper spirit" into their Clans--which is how Jango Fett came to be a Mandalorian. Think of them kind of like 'samurai'--an exclusive society of warriors with a strict code of behavior tied to a very specific cultural background. And Fett is not the last one, either....