Don't Make Me Think - Originally written in 2000, Don't Make Me Think is one of the original books on web design and usability. Although it's been around for a while, the goals and lessons of the book are universal and apply to websites today.
VisualSitemaps - Autogenerate visual sitemaps in seconds.
Coursera - "Compilers" by Stanford - The course explores how high-level languages are compiled to low-level assembly.
Codrops Blueprints - Free website concepts ready to implement or modify
The Elements of Typographic Style - The primary form of communication on the web is through text which makes typography one of the most important aspects to design for.
Octopus.do - Build your website structure in real-time and rapidly share it to collaborate with your team or clients. Start prototyping websites or apps instantly.