I have a tip on photographing through glass : don't take the photo square on to the glass itself, you will get a nasty reflection back particularly if your flash goes off. If you take the photo at an angle to the glass, the reflection of the flash will bounce off away from your camera. Try also to turn the flash off too, though it can get tricky to hold the camera still for long enough in low light.
Congratulations on the exhibit! Really is an exciting occassion,
Mental.