Since anyone can put whatever information they want on the Internet, not all web sites are created equal.
Some points to consider when evaluatiing the information provided by a web site:
Who is the audience for the information and what is their goal?
Is the information accurate and complete?
Is the information current?
When was the web site last revised?
Who is the author(s) or sponsor of the web site?
What are the credentials of the author(s) or creator of the web site?
Are there other online or print sources for the information?
For links to more in depth discussions about the evaluation of web sites
click on Evaluating Web Pages
MatWeb - Material Property Data includes a database of material property data sheets covering plastics, metals, ceramics and other engineering materials. The web site can be used freely without registration but users are required to register to use the advanced features. There is a charge to use some of the advanced features.
NIST Scientific and Technical Databases The NIST Data Gateway provides access to over 80 NIST scientific and technical databases. These databases cover a broad range of substances and properties.The NIST Gateway provides access to free databases created by NIST and PC based database available for sale. Some of the databases included are the CODATA Fundamental Physical Constants, the NIST Ceramics WebBook, and the NIST Chemistry WebBook. Search options for the Gateway include keyword, property, and substance name.
EFunda is an online source of basic engineering and engineering related information created to provide users with one-stop shopping for concise, reliable information. The site is not a portal to other websites. Major categories of information provided include Materials, Design, Processes, Units, Formulas, and Mathematics. Some services require the purchase of a membership.
The Engineering ToolBox is a commercial website that provides access to web resources, basic engineering information and applications. The site can be browsed by category or searched using the Google search engine. Many of the resources are linked to external websites including Wikipedia articles. The coverage is not comprehensive but this portal can help the user locate useful engineering information resources.
Byrne’s Electrical Engineering Hot Links is a collection of links to web sites useful to electrical engineers. Categories include: Antennas ASICs, Associations, Batteries, Boards, Books, CAD, Capacitors, Clocks, Cooling, Connectors, Discretes, Displays, Distributors, Enclosures, Fuses, Hobby ICs, Indices, Inductors, I.P. cores, JOBs, Magazines, Memory, Mechanical, Modules, Motors, Optiks, Programmable Logic, Prototyping, Schools, Relays, Resistors, Resumes, Sensors, Software, Switches, Test Equipment, Tools, and What's Cool?