National Center for Biotechnology Information (NCBI)
Baylor College of Medicine Genome Center (BCM)
Cold Spring Harbor Laboratory
The Sanger Centre
Harvard Biological Laboratories
The Jackson Laboratory WWW Server
DOE Joint Genome Institute (JGI)
European Molecular Biology Laboratory (EMBL)
European Bioinformatics Institute (EBI)
The ExPASy Molecular Biology Server (ExPASy.org)
Genethon WWW Server
The Biomedical Informatics Research Network (BIRN)

Harvard Biology Links
NCI-Frederick Scientific Library - excellent information resource
CMBO - An Informational Resource for Cell and Molecular Biologists, by Pamela M. Gannon
Computational Biology or Bioinformatics references - very comprehensive linkset, at UCSC