Originally Posted by ToastAir

Register at FaaSafety.gov. You'll get notice of lots of good seminars including ATC. I just recently did one on our class B and ATC communications. I happen to be an active line controller as well as a CFI II MEI. It's true a lot of times they send staff and others who are sometimes a little removed from what is currently happening, but a lot of good info is still available. Operation rain check is another good opportunity. If you don't ever see them for the facility you are interested in, give them a call. You may be able to arrange a tour. I think these things are great. If I can educate a pilot on what I do, it makes makes my job easier.