There are all kinds of goodies available free online. The entire world's Medical literature is at your fingertips thanks to the US National Library of Medicine. Searches and abstracts of articles are free. The entire text of articles is free for most journals indexed by PubMed Central. Merck Manuals, Gray's Anatomy, the current issue of the British Medical Journal, archives of the New England Journal of Medicine, etc are all free if you know where to look. All the sites listed below are recommended.
1. Free Medical Journal Searches The US National Library Of Medicine and NIH sites are the most popular medical websites in the world. This link is to PubMed Central, the searchable digital archive of the world's free health sciences literature. Find articles going back to the 1800s. You can download the free text of most articles. Search by title, author, subject, keywords, or field of medicine. According to a new NIH policy, all investigators funded by the NIH must submit an electronic version of their manuscript to PubMed Central within 12 months of publication. An amazing resource, and a worthwhile use of our tax dollars. Highly recommended.
2. PubMed This link is to PubMed which includes all of the world's biomedical literature both free and subscription required. It is a much larger database than PubMed Central, because only the free literature is in PubMed Central. You can get free abstracts and order journal articles online, or save the reference and request it from your local hospital library. Highly recommended.
3. Google Scholar In a short time this has evolved into a serious competitor for Pub Med above. A recent Review has compared the two search engines. Currently it is felt that PubMed has more journals indexed and is a better choice for use in guiding patient care, but this can change as Google adds new features and journals to its database.
4. SUMSearch is one the best medical metasearch engines. A metasearch engine saves you time by searching several other search engines at once. SUMSearch has the easiest user interface for a medical professional, allowing you to filter your search by intent, ie, treatment, diagnosis, prognosis, etc. There are no ads or spam.
5. Medscape Registered users of Medscape get free access to over 200 medical journals, including some major journals. See the following list of Medscape Journals. You also get pop-up ads and spam, but it is worth it to get free access to so many journals.
6. Merck Medicus Free Journals Over 150 journals are available free for registered users of Merck Medicus. No pop-up ads, and less spam than other drug company sites.
8. The Cochrane Library The Cochrane Reviews bring you the combined results of the world’s best medical research studies, and are recognized as the gold standard in evidence-based health care. Free to UK, Central and South American residents based on their ip address.
9. Bandolier A free online journal of evidence based medicine from the United Kingdom. It's target audience is both consumers and professionals. It does an especially good job in reviewing complementary medicine trials.
10. British Medical Journal The world's most popular online medical journal as judged by number of visits. Free
11. New England Journal Of Medicine The world's most influential medical journal, as voted by the Amedeo physician community. Free after six months, registration required.
12. Journal Of The American Medical Association One of the world's most influential medical journals, free after six months
13. Annals Of Internal Medicine Free after six months
14. Morbidity and Mortality Report The US Centers For Disease Control, free weekly journal. Free
15. CA: A Cancer Journal For Clinicians This journal from the American Cancer Society is free either online or in print. A good source for cancer statistics.
16. Amedeo, Free Weekly Literature Update This is an international free service that will send you weekly literature updates in medical subjects of your choosing
17. Free Medical Journals Amedeo's links to the above journals plus Science, Circulation, Blood, Archives Neurology, many others.
1 . Merck Medicus Free Textbooks Registered user's get free online access to Cecil Textbook of Medicine, Harrison's Online, Danforth's Obstetrics and Gynecology, Sabiston Textbook of Surgey, Wintrobe Hematology, all of the Merck Manuals, and many others. One minor quibble is that their online PDR omits many generic drugs. Highly recommended.
2. NIH The world's most popular and most objective medical reference site. There is such a wealth of information that it is worth spending time to get to know this site. You have to know a resource exists in order to find it. For example, PDQ is the world's most up-to date oncology reference, with separate versions for the layman and the health professional. No registration required, no advertisements, and no spam. Highly recommended.
3. Amedeo Free Books For Doctors From Amedeo, the world's largest online physician community. This organization, founded by Bernd Sebastian Kamps MD, is dedicated to the free dissemination of medical knowledge. Arranged by topic. Highly recommended.
4. eMedicine An open access comprehensive medical textbook with over 6500 articles, and 10,000 contributors. From WebMD, the owners of Medscape.
5. Bartleby's Great Books The world's greatest fiction and nonfiction literature free, online in one site. Gray's Anatomy, Roget's Thesaurus, Bartlett's quotations, Strunk's Elements of Style, the complete works of Shakespeare, the complete Harvard Classics of fiction, the great authors from Aeschylus to Virginia Woolf. A treat for scholars and students of all fields.