Oldie to observing, but newbie to photometry, that's me. Could be it's just the long holiday weekend that is holding up a reply from the AAVSO.
What I did when I knew I wanted to explore variable star photometry was watch this forum and follow the posts for a number of months. I found out who was in the know about the subject then made a point to contact that individual myself asking for "mentor" help. It worked out and by chance my helper has taught AAVSO classes and is a contributor to the AAVSO CCD Handbook. This has been just since Spring and I've received a ton-o-advice.
The first thing I did was perform a linearity test on my camera (Atik 314L+) and determine the ADU count where the CCD saturates. This is a must have bit of information. If you haven't found that out yet start there. Next, and which is where I am in the learning curve, is through testing on standard star fields find the optimum exposure time for your system (telescope-filter-camera) on various magnitudes at differing elevations (different air masses) so you can achieve best signal to noise ratio without saturating your target and comparison stars. Lot of prep work before actually beginning photometry I've discovered.
I'm using AstroImageJ software to calibrate and inspect my science images. For photometry I intend to use AAVSO's Vphot online software. For that purpose I too have just joined the AAVSO this last week.
Good luck, hope to hear more from you on your experience!!