http://www.microscopy.fsu.edu
interesting pages are:
confocal vs widefield
laser scanning confocal microscope simulator
Nikon microscopy University
Introduction to confocal microscopy
multiphoton excitation microscopy


http://www.loci.wisc.edu
interesting pages are:
optical, optical sectioning


http://www.drbio.cornell.edu
interesting pages are:
http://www.drbio.cornell.edu/pastcovers.html
infrastructure, typical microscopes