Starting a Monk WoW
The monk is a master of speed and can be melee DPS, tank, and healer. They use a variety of fighting stances to fit their situation, and excel at short-distance crowd control, evading damage, and abilities that combine healing with damage. They have few ranged attacks, but instead have abilities that allow them to quickly get into their opponent's melee range.
Every race except worgen and goblins has the option to be a monk. Keep in mind that the differences between the races is minor, and what matters most is to pick a race that you enjoy playing.
Monks do exceptionally well in groups on account of their hybrid status. While it would be impossible to keep up with every nerf or buff, in general the Monk class has always done well at performing all 3 roles in PVE; Tank, Heal, and DPS. In many encounters near the endgame, they may even be sought after for various reasons; i.e a Brewmaster's stagger, and Mistweavers lightining fast healing, and Windwalker for when you need a class to pick up adds quickly without much risk (due to Touch of Karma).