With this article from IDF, you'll get the basic definition of User Experience Design.

Jakob Nielsen's 10 general principles for interaction design. They are called "heuristics" because they are broad rules of thumb and not specific usability guidelines.

Ten principles for good design by Dieter Rams.

Level up your product skills with bite-sized tips. Learn the growth & design strategies used by the top product companies in the world.

Diagram about complexity of user-centered design for the Web from Jesse James Garrett.

Laws of UX is a collection of best practices that designers can consider when building user interfaces.

UX Myths collects the most frequent user experience misconceptions and explains why they don't hold true. And you don't have to take our word for it, we'll show you a lot of research findings and articles by design and usability gurus.

Guidance for designing ethically humane digital products and services through patterns focused on user well-being.

Ten laws of simplicity by John Maeda.