Electrical/Electronics:

• Maxim Resource Librariy - Nice collection of electronics design tutorials, tools and resources, on IEEE Spectrum.
  URL: http://spectrum.ieee.org/static/maxim-resource-library
• RAS - The IEEE Robotics and Automation Society
  URL: http://www.ieee-ras.org
• The IET - The Instituion Of Engineering And Technology
  URL: http://www.theiet.org
• IEEE - The Institue Of Electrical And Electronics Engineers
  URL: http://www.ieee.com