Want to know what resistor to use with some led? Take this calculator for a spin and see how it goes.
http://metku.net/index.html?sect=view&n=1&path=mods/ledcalc/index_eng
Illustrated tutorial with animation shows what radar detectors do and how they do it. Also explains lidar, jammers and detector detection.
http://www.howstuffworks.com/radar-detector.htm
Paschen's law is about high voltage breakdown distances in certain gases. Very interesting page.
http://home.earthlink.net/%7Ejimlux/hv/paschen.htm
Informative illustrated guide to how Digital Clocks operate including instructions describing how to build your own.
http://www.howstuffworks.com/digital-clock.htm
Provides information on the Basic Skills in Electricity and Electronics Series (Rainbow Series), and links to student and instructor sites.
http://www.glencoe.com/ps/bsee
Contains timing diagrams and a component calculator. Quite a few explanations.
http://www.westminster.org.uk/intranet/departments/electronics/555.htm
How to determine those pesky specs for your new transformer.
http://home.earthlink.net/~jimlux/hv/xfmrmeas.htm
University of San Diego Electrical Engineering course in RF and microwave circuit design
http://www.sandiego.edu/~ekim/e194rfs01/index.html