general

www.design-council.org.uk
The home page of the Design Council.

www.red-dot.de
A great source of good design examples

www.design-engine.com
This site has leaning towards CAD modelling and rendering, but has many interesting articles.

www.core77.com
In their own words, "an industrial design supersite".

www.csd.org.uk
The Chartered Society of Designers.

 

innovation and patents

www.innovation.gov.uk
DTI site promoting and advising on R&D and innovation.

www.cipa.org.uk
Advice on protecting your ideas from the Chartered Institute of Patent Agents.

 

manufacturing, engineering and materials

www.matweb.com
A great source of materials information and data.

www.rswww.com
An eternally indispensible place to buy almost anything.

www.practical-engineer.co.uk
Good resource for engineering information and materials.

www.efunda.com
Engineering fundamentals.

www.howstuffworks.com
The title says it all...

www.geplastics.com
A guide to the engineering plastics available from GE.

http://manufacturing.stanford.edu
A guide to how everyday things are made.

 

environment

www.cfsd.org.uk
The Centre for Sustainable Design.

www.defra.gov.uk
A government directive aiming to reduce the amount of electrical product land-fill.