No, this is not a how-to but the basic question of a survey. NPR reports that the Future of Music Coalition is trying to find out about revenue streams for jazz artists to get an accurate measure of how the field is doing. Take the survey if you're a jazz artist whose making any money (we hope there are plenty in the Berklee community), and spread the word.
Artist Revenue Streams - Future of Music Coalition
NPR story on the Artist Revenue Streams project