Unemployment is a measure of the rate of joblessness in the labor force. It is a lagging indicator that generally increases or decreases with the rest of the economy. Unemployment is typically uneven spatially and among demographic groups. There can be significant seasonal variation in unemployment. It is important to understand how the unemployment rate has changed over time, whether there are periods of the year where the rate is lower or higher, and if the seasonality of unemployment has changed over time. For the most recent unemployment rate, visit the BLS website directly. 

Questions to ask of the data…

Looking at a variety of indicators is useful. For example, after identifying a "high-growth" industry, you might want to also look at wages in that industry--the jobs may not be very high paying, and the growth may not be as great of a local boon as it appeared.