One indicator that you can use is
rudder angle. When close hauled if you have more than around 5-7 degrees of
rudder, start dropping the traveller. When you get to the end of the traveller and you still have a lot of rudder angle, then it is time to reef. Rinse and repeat as the
wind intensifies, going to the second reef if required.
You are a bit hampered by the roller
genoa, for by the time you are travelled down and one reef in, the next step should be reducing the headsaill, and rolling it up is a poor way to do that compared to switching to a smaller one. Obviously you won't be doing that, so roll it with some tension on the sheet to get a tight roll and continue as above. You may note that the boat will do slightly better on the tack where the roll is on the windward side of the sail, but it will not be a big difference.
So the next step is to develop a close relationship with both your
sailmaker and your bank manager...
Enjoy the
racing -- you will learn lots and have some fun too.
Jim