The Bureau of Labor and Statistics has a great site for getting useful stats.
For instance, you can find a graph that shows you the ratio of working people to the population, charted over time, from 1995 to 2005. It is very interesting. It went from 63% to 64.5% from 1995 to 2000, then dropped precipitously. It's raised a bit in the past couple months, back up to 62.5%. If you go back even further, you can see it raise for Carter, drop in the beginning of Reagan then raise again, drop of Bush I, raise for Clinton, then drop for Bush II.
The interesting thing about this graph is that it gives you a useful number. The unemployment rate, which is the most commonly cited statistic, only counts those people looking for a job, and thus doesn't count those who have given up. The total number of jobs is a better number, because you can see if we're increasing of decreasing jobs. But, if the population increases by 100,000 people, and the total jobs increases by 50,000, we still have 50,000 more unemployed people than before. The ratio of employed people to total people tells you how the economy is doing much better.
No matter what the Republican party tells you, our economy has not improved since 9/11.