This is the world's primary website for information on observing comets. First, check out the main ICQ Comet Information page at http://www.cfa.harvard.edu/icq/icq.html for general information on comets, with some emphasis on observing comets photometrically, with lots of links to our other pages regarding reporting astrometry and discoveries of comets, ephemerides and orbital elements for comets, etc.
See also our Index, or consult the list below (which includes many aids to comet observing):
Think you've possibly discovered a comet?
Comet designations and names
Green, D. W. E., ed. (1997). ICQ Guide to Observing Comets.
Index to the CBAT/MPC/ICQ pages.