Evidence-based practice is patient care based on research. It helps medical practitioners to make practical decisions based on the best available evidence. There are two types of sources you would want to look for: systematic reviews and clinical trials.
Primary Sources:
Secondary Sources:
Google's index of available research:
Links to government agencies:
http://nccam.nih.gov/health/links
Pub Med Resources (government index of medical research):
http://www.ncbi.nlm.nih.gov/pubmed/
Information about FDA approved drug products:
https://www.accessdata.fda.gov/scripts/cder/drugsatfda/
U.S. National Library of Medicine: Drugs, Herbs and Supplements Database:
https://www.nlm.nih.gov/medlineplus/druginformation.html
Summaries of the latest medical research:
http://www.sciencedaily.com/news/health_medicine/
The "google" of government documents: