University of New South Wales (Australia)
University of New South Wales: Flute Acoustics
This site from the University of New South Wales describes, defines and gives an introduction to flute acoustics. A great site, it also provides many links to necessary information on the subject.
Other
Mark Shepard's Flute Page
At this website "you'll find resources for playing the flute and for making simple folk flutes." Includes a "Flute Fingering Chart" that you can download.