CDER: Center for Drug Evaluation and Research
Drug information for consumers from the Food and Drug Administration

Drug Digest
Contains drug interaction library, drug/food interactions, side effects, generic info, pictures of pills and uses for medications.

Mayo Clinic
Find information on more than 8,000 prescription and over-the-counter drugs from Micromedex Inc.

Merck Manual Home Edition
Based upon the Merck Manual of Diagnosis and Therapy, commonly referred to as The Merck Manual. The Home Edition transforms the language of the professionals' version into commonly used English while retaining the vital information about diseases, diagnosis, prevention, and treatment. The Merck Manual of Medical Information--Home Edition, like all the Merck Manuals and The Merck Index, is published by Merck & Co., Inc., on a not-for-profit basis. Available in both a text and interactive module.