Literature databases

National Library of Medicine Pub Med
Search for Literature in MEDLINE and other databases.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed

Cancerlit
The literature database of the National Cancer Institute.
http://www.cancer.gov/cancerinfo/literature/

Free Medical Journals
A directory of free full-text articles from numerous journals.
http://www.freemedicaljournals.com/