The Merck Manual Online - Clinical Pharmacology
According to the site, "Merck is committed to bringing out the best in medicine. As part of that effort, Merck has created The Merck Manuals, a series of healthcare books for medical professionals and consumers. As a service to the community, the content of The Manuals is now available in enhanced online versions as part of The Merck Manuals Online Medical Library."
This manual concerns Clinical Pharmacology and contains topics such as: Adverse Drug Reactions, Pharmacodynamics, and Pharmacokinetics.