Exceptionally good free resource on interactive design and UI/UX @interacting
The Interaction-Design.org Foundation is a labour of love founded by Mads Soegaard in 2002, and in 2010, his wife, Rikke Dam, joined the project. Apart from Rikke and Mads, hundreds of people have helped out and continue to do so.
We're on a mission to make free and open educational materials: There are so many great minds in the Human-Computer Interaction and Interaction Design community and we want to empower these authors to reach all their interested readers around the world. We believe these authors have the minds to change the world and deserve a publishing venue truly designed for the author and the reader, not the publisher and the profit.