A complete listing of the great many astronomy-related websites useful to observers is far beyond the scope of this page. What follows is a selection of those we've found most useful. For a much more comprehensive listing, we suggest the AstroWeb, a database of astronomy links maintained by the AstroWeb Consortium.
(Weather links are listed separately.)

LITERATURE, CATALOGS, DATA, SURVEYS, TOOLS

Astronomical Almanac
VizieR
SIMBAD, France
SIMBAD, Harvard
ADC
ADS Abstract Service
ADS Article Service
DSS, STScI interface
DSS, CADC interface
NED
Ephemeris Generator
UCSC Science Library

UNIVERSITY of CALIFORNIA ASTRONOMYTOP

Center for Adaptive Optics at UCSC
LLNL Astrophysics
LLNL Laser Guide Star/Adaptive Optics
UCB Astronomy
UCB Space Sciences Laboratory
UCI Physics and Astronomy
UCLA Division of Astronomy and Astrophysics
UCLA Infrared Imaging Detector Laboratory
UCO / Lick Observatory
UCSB Dept. of Physics
UCSC Dept. of Astronomy and Astrophysics
UCSD Center of Astrophysics & Space Sciences

Institutes of Geophysics and Planetary Physics (IGPP's): LLNL | UCLA | UCSC | UCSD | UCR

MAJOR OPTICAL OBSERVATORIESTOP

AAO
Apache Point
Calar Alto
CFHT
DAO
ESO: La Silla
ESO: Paranal
Galileo
Gemini
HST
Isaac Newton Grp.
Keck
Las Campanas
Lick
Lowell
McDonald
Mount Graham
Mount Wilson
MMT
NOAO: CTIO
NOAO: KPNO
Palomar
Subaru
UKIRT
Yerkes

OTHER ASTRONOMY LINKSTOP

AURA
Caltech Astronomy
Canadian Astronomy Data Centre
CfA
ESO
Herzberg Institute
IPAC
NASA Goddard
NOAO
SEDS
Sloan Digital Sky Survey
STScI