From a current astronomy professor (Score 1)

I am an astronomy professor at a large state university. There are many way in which you can contribute to astronomy as an amateur, while at the same time learn about astronomy. Some have been mentioned in previous answers in this thread:

http://www.planethunters.org/ it is a citizen scientists project that uses actual data from NASA's Kepler Space Telescope to find extrasolar planets that may have been missed by the automatic software used by the professional astronomers. It harvests the "wisdom of the crowd" and the natural pattern recognition in the human brain to find the telltale signature of extrasolar planets that the automated software may have missed. Some planets have already been found this way, and the citizens that found them have been included in the scientific publication: http://arxiv.org/abs/1210.3612

There are other 9 projects using the same infrastructure that use astronomical data to do real research: https://www.zooniverse.org/pro... . Topics go from stars, planet and galaxy formation, solar physics, black holes, asteroids, etc... All these projects use actual data from ground and space based telescopes, and have ample tutorials that explain how the project work and the science behind it in an accessible way. We use this projects in our school to introduce freshmen undergraduates to research as soon as they arrive to our university.

If you own an amateur telescope you can also contribute to the American Association of Variable Stars Observers (AAVSO: http://www.aavso.org/) which despite its name is open to amateur observers all over the world. The association collects data from amateurs to create lightcurves of variable stars. This is an exceptionally important work, because monitoring of bright stars is often overlook by the professional community; yet knowing long term trends in their luminosity is essential to understand stellar evolution, stellar physics and the cosmological distance scale. The AAVSO is organized as a scientific society, and as such has a journal where results are published, scientific meetings, etc. It also has a lot of background material written in a way to be accessible for the public.

That said, I read in the comment thread above that somebody got discouraged in pursuing an academic career in astronomy because "there are no jobs". This is not true. The field is not worse than any other academic field. Surely we are suffering from cuts in science expenditures an education, like anybody else (hint: think about that when you vote next November), but universities, observatories and agencies like NASA are still hiring. New people can still make it in the field, and even if they don't find a job as astrophysicists there are many careers in the private sector where the skills learned while pursuing a Ph.D. in astronomy are welcomed. One collaborator of mine, for example, just got hired to work at a cool startup company in the D.C. area. A student of mine went to work at Lincoln Lab in Boston on remote sensing. Other ex students in our department that decided to leave research went to work in medical imaging (at Mayo clinic), or even making battle plans for F14s on a aircraft carrier (his claim of fame is that he prevented the Navy from declaring war on Venus). Our university, as well universities all over the world, still accept scores of new student in astronomy programs: not everybody remains in astronomy after their degree, but as far as I know the unemployment rate for professionals with an astronomy Ph.D. is close to zero.

One thing about astronomy is that is a very inclusive community: differently than physics, we have an almost equal gender ratio among the young generations. Age also is not a problem, one of the graduate students we admitted this year is a retiree that decided to complete his studies after working for decades in the oil industry. He is having the time of his life.