Right now the highest speeds available in a wireless network solution is 108mbps. Remember that the speed is the theoreticly max. You will never reach that speed.
For every obstacle in the way, wood, concrete, glass, rain, humidity, will make the signal weaker. Always try to have "eye contact" for the maximum preformance. The standard WiFi products of today usually has a maximum range at 400 yards(although it's possible to extend the range with a different antenna). There are known bridge stations that can establish a stable signal at a distance of 10 miles or more.
There are diffrent types of antennas, they go in to two sections:
Omni directional - antennas that sends the signal in every direction, 360'. these antennas are usually included with the base station, excellent when you want to move around.
directional antennas (don't know the name in english). That only sends in one direction, usually used for connecting another base station or extending the signal in one direction.
Can't think of anything more to add, just ask!