Science 

About Chemistry

American Chemical Society: Chemcyclopedia Online - searchable database of chemicals and their suppliers.

Botany Encyclopedia of Plants and Botanical Dictionary - information on plants, cultivation, propagation etc.

Cambridge Astronomy

EarthTrends: The Environmental Information Portal

How Stuff Works - engines, clocks, domestic appliances, electronic gadgets and much more.

The Met. Office Home Page

Ned Wright's Cosmology Tutorial

Scientific and Technical Acronyms, Symbols and Abbreviations

SciTech Daily Review - science, technology, future developments, innovations, implications.

 Medicine 

HerbMed - evidence-based herbal database.

MedTerms - medical dictionary.

TOXNET - databases on toxicology, hazardous chemicals, and related areas.

Typing Injury FAQ - contains information about repetitive strain injuries, resources and products to reduce injury risk and symptoms.