Just like everyone told me to do when I asked the same question...You can use the Airnav website to lookup frequencies to your local airports, where you will hear milair from time to time. Also you can look up in the wiki the uhf artcc frequencies that milair usually use. Other than that maybe someone could hook you up with some freqs', maybe someone who lives by or around you.
This is one area where the scanner and antenna makes all the difference - an antenna nice and high outdoors, fed with the right coax is the best solution. However, even an indoor antenna will hear milair if you know where to look, assuming you have a scanner that's capable of hearing these ranges.
I would read up on the subject here (anything in blue is a link)...
It's always better to get info from the locals in the area.
Re the ARTCC listings; the FAA supplied listings aren't always that accurate - this has been noted by several folks, including most recently, Larry Van Horn in his mil column at MT. Scroll past them and use the freqs that follow it.
Well, if you don't want air traffic control then there is our day-to-day use of LMRs (Motorola/EF Johnson).
Most military comm like that is trunked - primarily Motorola systems; SmartNet/SmartZone/P25.
There are one or two MA/COM systems out there and rumor has it that the USAF is looking at EFJ P25 trunking.
Get a good scanner and you should be able to monitor local systems unless they're encrypted or frequncy hopping - then you aren't going to hear diddly squat.