Human Teams have appeared in Bloodbowl since the very beginning of the game, and according to fluff were among the earliest and most enthusiastic adherents of the sport. They first appeared as playable teams in 2nd edition.
Human teams are, essentially, just what their name implies: teams made up of Humans. In earliest versions of the Games Workshop fluff, Ogres were distantly related to humans, and as such, Ogres were known to play alongside Humans in Bloodbowl matches. Over time, the relationship between Ogres and Humans has been muddied by various incarnations of the fluff, but Human teams are still permitted to hire Ogre players for their rosters.
Although most Human teams are said to come from the Empire, a pseudo-Renaissance Germany in the Games Workshop universe, a number of Human teams are also said to come from Bretonnia (a country not unlike medieval France), Tilea (Italy), Estalia (Spain), Araby (guess?), and other lands. Although there were some experimental rules for Brettonian teams published in various official sources, the basic Human team roster remains the only option for players wishing to field predominantly Human teams.
Humans are perhaps best known to current players of Bloodbowl because they were one of two plastic teams included in the 3rd Edition boxed set, the only set currently available directly from Games Workshop.
0-16 Human Linemen
0-4 Human Blitzers
0-4 Human Catchers
0-2 Human Throwers
Play Style and Tactics
Humans are alternatively one of the most flexible and one of the most frustrating teams with which to play Blood Bowl. Their players are neither particularly good nor bad at speed, throwing, or catching, neither (with the exception of the Ogre) are they better than average in the strength department. Most humans have an Armor Value of 8, meaning that they are about average in this department as well. This means that they are very flexible, and can be played in a variety of ways. It also means, however, that they are not particularly outstanding at any one type of play, and require cunning, tactical forethought, and more than a small dose of luck in order to be used effectively.
Famous Human Teams
The Reikland Reavers are probably the most famous Human team, owing to their promotion by Games Workshop. One of the earliest and most famous Human teams is the Bright Crusaders, a team known for such high morals that in early days they refused to foul or block aggressively, leading to a predictable string of losses and unfortunate incidents on the field.
There have been a number of iterations of official sculpts for the Human team over the years. One of the most recent offerings from Games Workshop depicts the Humans in a style reminescent of their earliest sculpts: stylized plate mail sculpted in a style reminescent of American football equipment with the occasional addition of spikes and pointy bits.
Strangely, there aren't many alternative Human teams available to players beyond Games Workshop. One possible source is Impact, which produces a Samurai themed team and an Arab theme team that paint up beautifully. Black Scorpion's recently released Human/High Elf team is also quite nice, though very different from the standard fare.