JQuery Fundamentas by Rebecca Murphey

HTML5 is attracting more and more attention. I am very excited to see major browsers implement HTML5 in the future, just like C++11 becomes an improved standard and it gives a great boost for the C++ community and compiler writers.Yes standard is slow to finalized, but it does pay off in the long run. Now HTML5+CSS+Javascript present great potential, and Adoebe announce they will not support flash in mobile devices but heavily invested in HTML5.   

Javascript therefore becomes an important tool for web developers/designers. It is not as clean as Python/Ruby but Javascript can do amazing stuff. You can build an javascript application, and ready to ship instantly on major browser. Learn to write clean javascript, regardless which javascript framework you might pick later.

JQuery Fundamentals

Rebecca Murphey has a nice article on JQuery. It's hard not to use javascript with JQuery nowadays. I like the article. The content is rich, but still a quick read from start to end.

http://jqfundamentals.com/

Also spend a few minutes reading the JQuery source. It's a great library coded with efficiency in mind.
http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.js

Learn how to write, debug, build efficient code in web browsers. Stick to the standard while you can, they won't disappear overnight. :)