For general scientific information, try
NerdWorld's Chemistry page is a truly massive compilation.
The Chemistry Information Retrieval Server, based in Athens, Greece, is well-organized and comprehensive. It's also on a fast server with minimal graphics, so download time is nice and short!
The University of Liverpool's Department of Chemistry has compiled their own list of Links for Chemists.
Here are pages I have prepared on
Six different versions of the Periodic Table:
Links to other chemical information:
Maintained by Daniel J. Berger