Here are some of my favourite programming references:

<ul>JavaScript</ul>
Learn on: <a href="http://jsfiddle.net/">http://jsfiddle.net/</a>
Learn about js closures. The big problem is that the Java engine is separate from the DOM engine (which is the representation of the webpage), so when references get broken things can be left hanging and you get memory leaks.

Douglas Crockford’s web site:
http://crockford.com/
His book is st: http://www.amazon.com/JavaScript-Good-Parts-Douglas-Crockford/dp/0596517742
Also see YouTube - interesting part is MONADS.
http://www.youtube.com/watch?v=v2ifWcnQs6M

May be better learning jquery (a library) or angularjs (google jsframework). Sencha is based on a kind of scaffolding. Each page item is an object.