Available to the Black Research Group
Centers for Disease Control - "Your Online Source for Credible Disease Information" - huge site, operated by the NIH, featuring up to the minute data on every health challenge anywhere in the USA and world.  Many rotating education links for Health & Safety Topics, tools, resources, publications, and video shorts on timely topics like heart disease, diabetes type 2, etc.  Excellent search engine, featuring the top 20 searches, like autism, MRSA, breast cancer, HPV, TB, etc.
ChemACX is a comprehensive online catalog containing the most up to date product information from 358 of the top chemical supplier catalogs serving the research community. It contains over 326,000 unique chemical substances (21,000 NEW!), over 638,000 products (42,000 NEW!), and is updated two times per year.
ChemBioFinder is an all-around information locator for biologically active molecules and structures. The databases to be queried, whether for biological reference data, sourcing and safety information, or reaction/synthesis parameters, can all be specified via a series of checkboxes. Can be searched via text string or structure/substructure. Oh - and it's free!
ChemINDEX is a directory of over 75,000 unique chemical substances, listing chemical structure, 3D structure, registry numbers, synonyms, physical properties, and links to Internet sources of further information. ChemINDEX also provides additional access to the NCI database with integrated AIDS and Human Tumor Cell Line screening results. The internet edition also has links to ChemACX and The Merck Index.
ChemReact68, from InfoChem GmbH, is a database of sample reactions comprising essential information on 68,000 reactions, selected because they have greater than 50% yield and have appeared in more than five example reactions. The database consists of reaction information and literature references.
ChemSynth* One of the coolest databases I've seen in a long time. To be included in their database, a reaction must have appeared at least twice in a leading journal with a yield of over 50%.  The database encompasses reactions published between 1974-2001; the total number of reactions to choose from is over 180,000!!  [Unfortunately, this application tends to run best on IE, so I've set it up so it brings up a new window when you click it, and you can specify IE if necessary.]
The Merck Index contains 10,955 monographs describing significant chemicals, drugs, and biological substances. The entries are not a listing of Merck & Co., Inc. products, but rather cover a wide range of compounds, which have been selected on the basis of present or historic importance and interest.
Merck Manual, The
Partner book to the Merck Index, the Merck Manual covers all aspects of disease or other pathology: etiology, diagnosis, lab tests, treatment, prognosis, etc. Extremely useful, especially since the on-line version is searchable, with the results listed according to % relevance.
As the drug discovery and development arm of the NCI, the Developmental Therapeutics Program (DTP) plans, conducts, and facilitates development of therapeutic agents for cancer and AIDS. The data in this database (available from http://dtp.nci.nih.gov/) focus on research in the following two categories: DTP Human Tumor Cell Line Screen  and  DTP AIDS Antiviral Screen.
Organic Syntheses
Provides the chemistry community with annual collections of detailed, reliable, and carefully checked procedures for the synthesis of organic compounds. Some procedures describe practical methods for the preparation of specific compounds of interest, while other procedures illustrate important synthetic methods with general utility.
Synthetic Pages*
(interactive database of synthetic procedures)

SyntheticPages is a free database of practical procedures for research workers in synthetic chemistry. You can find the database at http://www.syntheticpages.org.  It is not peer-reviewed; rather, it is an exchange of current methods that have worked for various researchers.  Medicinally-oriented.
Traditional Chinese Medicine (TCM)*
Contains information on 10,458 compounds isolated from 4,636 TCM natural sources, comprised mostly of plants, a small number of animals and a few minerals.   Features molecular structures, natural sources, and applications.  Fascinating!
*These services are subscription-only, so if you're not in the Black group, don't bother trying to access them. Black Group members: you have this info; if you've forgotten, ask me or another group member.