The key medical sites described in this article are only the tip of the iceberg. To use the Internet effectively for medical information it is necessary to search the subject-based gateways. These sites do some of the hard work for you, by seeking out, evaluating, describing and indexing resources.
OMNI - Organising Medical Networked Information , is the eLib funded biomedical gateway. It offers access to more than 1300 resources in health, clinical medicine, allied health and related areas.
Medical Matrix  - a US based gateway - is particularly good for clinical medicine.
Health on the Net , a new venture based in Geneva, is also well worth a visit.
There is so much good medical information on the Web that picking a few sites is very tricky. However, here are some 'must have' sites in clinical medicine, health promotion and news.
The various agencies of the  provide an unparalleled collection of information, reflecting the size and stature of the organisation:
- The Federal Defence Agency's Bad Bug Book  provides a handbook of basic facts about foodborne pathogenic micro-organisms and natural toxins.
- The Centers for Disease Control and Prevention produce an AIDS Daily Summary , giving news about HIV and AIDS compiled from various press and news agencies.
- The Agency for Health Care Policy and Research  has a document server which contains many clinical practice guidelines.
A more modest offering from our own Department of Health (DOH)  has attracted much praise. Completely searchable, the DOH pages contain a wealth of official information, such as white papers and press releases.
Medical intervention based on evidence is the key concept said to be driving many health service and medical education reforms. The Cochrane Collaboration Web Site  in Canada is a key resource in this area. In the UK, we have the Centre for Evidence-based Medicine.
The World Health Organisation (WHO)  publicises its various programmes and centres through a very impressive series of pages. Like the US Department of Health and Human Services, each WHO organisation produces its own pages, which are then linked together to form a distributed but easily navigated collection.
Keeping up with breaking news in medicine can be tricky. The Reuters Health Site  can help - news items are searchable, and the service is updated on a daily basis.
For a fuller review of news services relevant to health and medicine, see OMNI Newsletter No. 4 .
With all this exciting and free information available, we should not forget traditional sources. The printed journal is still the most likely place to find peer reviewed research articles. Many commercial secondary services can however be used via the Internet though. The UK HE sector has Embase and BIOSIS from BIDS  and  respectively, and the British Medical Association operates a dial-in Medline service for its members.
In addition many journals are now going on-line. You can read selected material from The British Medical Journal , The Lancet  and The New England Journal of Medicine  on the Web. OMNI produces a booklet listing around 50 high quality medical sites, together with information about OMNI, which we post free to all UK addresses. Multiple copies, for training purposes, can be supplied (up to a limit of 50). Please e-mail your request to firstname.lastname@example.org stating your full postal address and the number of leaflets you require.
 OMNI Health/Medical Subject Gateway,
 Medical Matrix Gateway,
 Health on the Net Web site,
 US Department of Health and Human Services,
 Federal Defence Agencys Bad Bug Book,
 CDCP AIDS Daily summary,
 Agency for Health Care Policy and Research,
 UK Department of Health,
 Cochrane Collaboration Web site,
 World Health Organisation,
 Reuters Health site,
 OMNI Newsletter No. 4,
 BIDS Web site,
 EDINA Web site,
 British Medical Journal Web site,
 The Lancet,
 The New England Journal of Medicine,
Sue Welsh is the project officer of OMNI, an eLib project