The Encyclopedia of Human-Computer Interaction, 2nd Ed.
Free textbooks written by more than 100 leading designers, bestselling authors, and Ivy League professors. We have assembled our textbooks in a gigantic encyclopedia, whose 4,000+ pages cover the design of interactive products and services such as websites, household objects, smartphones, computer software, aircraft cockpits, and what have you. Name an item of design interest, and you'll probably find it discussed inside.
“I highly recommend the Encyclopedia of Human-Computer Interaction [...] the breadth and the depth of the invited contributions are quite impressive [...] all with highly qualified authorities as authors.”