I like it; it's a good framework for building web applications where you need to re-use widgets. Whereas YUI (which I'm forced to use at work), jQuery are handy for generating for single-page apps.
I would have a look at "The UX Book: Process and Guidelines for Ensuring a Quality User Experience" by Rex Hartson & Parha Pyla. I picked it up on Safari Books a few weeks ago; it really gives you an in-depth look at both the theory and processes involved in UX design.