I have recently revised my tips on drilling glass. The first has links to the others.
http://glasstips.blogspot.com/2008/08/drilling-glass-1.html
These articles include comments on keeping the glass wet, use of drill presses and h0w to drill without one, use of a flushing head and core drills, ways of avoiding chipping or break-outs, various drilling tools, critical factors on hole placement, and recommended drill speeds for different sizes of drills. I hope you might find them useful
Stephen
