Here are some very detailed databases/maps/data for
objects in the sky. You will need RA/DEC (sky coordinates)
or object "name" such as Messier, NGC, or IC number to begin your search.
The SIMBAD (Set of Identifications, Measurements, and Bibliography for Astronomical Data)
site provides detailed info about many objects.
The Astronomical Data Center
is a huge resource of charts with links to several other sites.
The Astronomical Data Service
provides abstracts and links to many other sites.
The Astrophysics Data
Facility provides data from several satellites plus links to
The Extra-Galactic Database
provides additional charts plus data from a variety of satellites.
The Multi-Wavelength Sky
Database provides another powerful sky resource.