Worldwide Patent Database
Searchable database of patents on file
More Patent Databases (industry and country-specific)
FIling for a provisional patent
US Copyright Office
Promotes protection for the arts and for authored works
US Patent and Trademark Office
All about patents, trademarks, copyrights, and inventor resources and support.
US Trademarks
The official (and searchable) US Code on trademarks posted by Cornell Law School
World Intellectual Property Organization
Promotes the protection of intellectual property throughout the world
National Institute of Standards and Technology
Advancing measurement science, standards, and technology