There are two basic types of water meters. One is "straight read", which is read like the odometer on your car. The other type of meter is a "dial meter". To read this meter start with the dial labeled with the largest number (10,000,000-10) and read clockwise to the lowest numbered dial. If the needle points between two numbers, read the lower number.
To compute how much water has been used in a given period, subtract the reading at the start of the period from the reading at the end of the period. Meters are read to the nearest 100 c.f. One cubic foot of water equals 7.5 gallons of water.