I wrote my own chapter on JavaScript for Inside VBScript with ActiveX.
I also was technical reviewer for ...
I particularly like Bob Friesenhahn's article in the February 1998 Byte. More recently, Christophe Williams establishes the context for what a Webmaster needs to know about all the places JavaScript appears, whether on client- or server-side, or in WSH. He also distinguishes the different vendors (Netscape, Microsoft, Sun, Opera, ...) and their engineering focuses.
On-line resources: