My definite choice is the javaScript Bible Gold , 2001 Edition , by Danny Goodman . It has around 2100 pages , enclosed CD-ROM with samples , and it takes you from the "Hello , world!" type of script to building tree-style navigation bars , much like the one in UT . Then you'll see how horrible it is with the different DOM implementations .

Anyway , before anything , try http://developer.irt.org/script/script.htm .