I'm looking for tutorials on everything from the theory to the technicalities involved in the design process.
I should be noted that "tooling" and "technique" are different than "design." That said, is it possible to tutorialize design?
This blog is less about visual design and more about process in general: http://www.designstaff.org/
You can find some good stuff at http://teamtreehouse.com/ but it's more about the basics, I believe.
I've seen tuts+ mentioned occasionally but can't vouch for its quality: https://tutsplus.com/courses/?q=true&filter_topic=3