Starting off where we left off last time, we continue exploring the possibilities of jQuery. We revisit some of the old functions and make them do some smarter things. We explore a simple variable and an IF/ELSE statement. Then we look at the AJAX-y .load() function, the CSS function, and then finish off by writing out own custom function and going over how that layer of abstraction can help us keep our code clean. Semantics counts in JavaScript too!
http://css-tricks.com/video-screencasts/35-intro-to-jquery-2/