The Inventors Handbook (http://www.epo.org/topics/innovation-and-economy/handbook.html)
Highly recommended. A basic guide to the key stages of turning an invention into a commercial product, written by Graham Barker, author of a "A Better Mousetrap."

ideas21 (http://www.ideas21.co.uk/)
ideas21 are a UK invention and innovation network supported by government, industry and private organisations to inform and educate its members on all areas relating to the successful progression from idea to commercialisation.

Institute of Patentees and Inventors (http://www.invent.org.uk/)
A not-for-profit association for inventors.

Mandy Haberman (http://www.mandyhaberman.com/)
The website of a successful award-winning English inventor who triumphed against the odds in both the marketplace and the courts.

A Better Mousetrap: the business of invention (http://www.abettermousetrap.co.uk/)
Assesses inventions, advises inventors and publishes the indispensable inventors’ guide A Better Mousetrap: the business of invention.

The Trevor Baylis Foundation (http://tbf.websfor.org/_user/thetbf_site/lfb-cms.asp?data=1)
An organisation for inventors set up by the inventor of the clockwork radio.

Wessex Round Table of Inventors (http://www.wrti.org.uk)
Useful gateway site to ‘Inventique’ the free inventors’ newsletter and also listings of other UK inventors’ groups.

Alliance against IP Theft (http://www.allianceagainstiptheft.co.uk/aa_about.htm)
A coalition of British trade associations and industry enforcement organisations dedicated to protecting intellectual property rights.