Sources of Patent & Trademark Information
European Patent Office
A collection freely open to the world.
US Patent Office
US Patent & Trademark Office (USPTO). Patents from 1790 through 1975 are searchable only by Issue Date, Patent Number, and Current US Classification.
MIT Libraries Video Tutorials
Short video tutorials for performing patent and trademark searches. Some of the information is specific to MIT, but much of it is universally applicable.
Books on Patent Searching