I just wanted to share an amazing website http://www.digitaltutors.com/
It has amazing well thought out detailed video tutorials for almost any digital art program out there (XSI, Zbrush, photoshop, Maya, UDK, etc). It cost around 200 bucks for a 6 month subscription, but you get access to their entire library of over 30,000 videos.
I have used it briefly in the past, but recently I have been learning more and more through the site. They literally cover everything you would need to know.
Finding good free tutorials online is a challenge when it comes to learning software, and when you do its not done very well. These guys really know how to teach. If you are interested in seriously bettering yourself when it comes to whatever medium of digital art you do, I really recommend checking these guys out. Its well worth the investment.