There are many resources available on the Internet. The websites listed below are only an example and not meant to be an exhaustive list. At the time of this writing all of the websites listed are currently active, however due to the transitory nature of the Internet; this may not be the case at any future date. Additionally, information from the Internet needs to be evaluated critically, with attention to origin, author, motive, bias, and age.
A product of the National Center for Biotechnology Information, this site provides searching by BioAssay, Compound, and Substance.
Entries include Identification, Related Records, Use and Manufacturing, Pharmacology, Biomedical Effects and Toxicity, Safety and Handling, Exposure Standards and Regulations, Literature, Patents, Biomolecular Interactions and Pathways, Biological Test Results, Classification, Chemical and Physical Properties, 2D and 3D structure and much, much more.