Phlearn.com is the Photoshop education site of Aaron Nace. Quite simply, he is the most entertaining teacher of Photoshop that I have ever come across. He takes complex techniques and makes them simple to understand, and shows how to apply them in practical applications. Additionally, his PS tutorials keep you interested in the topic, unlike many other PS tutorials.
I highly recommend that you follow his PHLearn channel on YouTube.
I have purchased one of his tutorials that he has for sale, and it is very comprehensive and easy to follow. In my opinion, if you want to learn a lot of PhotoShop techniques correctly, and you want them in an easy-to-understand format, Phlearn is one of the best options available today.
Focus On is an showcase where I spotlight other photographers/artists/forums/individuals that I follow and learn from, as well as companies, tools, and applications that I use.