This is a valuable resource http://javascript.crockford.com/code.html
Here are some really good presentations: http://www.metafilter.com/61049/Douglas-Crockford-Teaches-Ja...
The code hasn't been obfuscated or compressed, and most of it is fairly straightforward and readable, except for the parts where the deadline started creeping up on the project. There the code gets a little ugly/hacky. AFAIK, IE 6, Safari, Firefox 2/3, etc. etc. all like it fine.
I wrote it, and I'm not particularly proud of it, but I've received enough (local) requests for it that a version 1 is in the works.
I'd actually check out the source to some of the major JS libraries: JQuery, Prototype, OpenLayers, etc. Most sites build off them, but the sites that know what they're doing will be packing/minifying their JavaScript, making it a bit hard to read.