Dave Weckl has a great video for tuning drums
In response to your harmonic problem.
I'v always found it handy to look at the top and bottom heads of the drum as providing 2 different functions. Tune the top head, so that its tight enough to get a nice rebound from
your stick and try to make sure that the drum ring is evenly placed on the drum. While tuning you might want to look at the drum from its side to make sure its even.
Now use the bottom to fine tune the sound of your drum. The tighter the bottom the higher-pitched it gets. That should get rid of your harmonics or help you find it and tune it out. If your still getting a slight ring then listen to which head its coming from. Once you find the ringing head then its usually 2 tuner bolts that are right next to each other that are too tight. You need to re-balance the tuner bolts by loosening and tightening them. Play around with it until the ring goes away.