> What text editor or IDE do you use?

 - [Microsoft's Visual Studio][1]
 - [Aptana][2]

Both have support for complete web app development features (javascript, HTML, CSS etc).
Choose Aptana, if you are looking for freeware solution.

> What unit testing framework do you use?

 - [Selenium][3]

 1. Has multi browser supoort [ IE, Firefox, Chrome, Safari, Opera and Konqueror ] on multiple platforms [Windows, Linux, Macintosh etc.].
 2. Support for many programming languages to write test cases [HTML, Java, C#, Perl, PHP, Python, Ruby etc.].
 3. Remote execution (test cases reside on one machine and execution on browser can happen in a different machine).
 4. You can run regressions even in browser minimized mode also

> What other tools do you use?

 - You can Use some UI Library framework like JQuery, YUI, Prototype etc for quick development.
 - Other tools: Fiddler, HTTP Watch, Firebug, IE Dev Tool Bar, JSLint, YUICompressor

> What books do you read/refer to?

 - [Javascript The Definite Guide][4]
 - [Object-Oriented JavaScript: Create scalable, reusable high-quality JavaScript applications and libraries][5]

> More

 - [Best Videos on javascript from Douglas Crockford ][6]
 - [YUI Theater][7]


 [1]: http://www.microsoft.com/visualstudio
 [2]: http://www.aptana.com/
 [3]: http://seleniumhq.org/
 [4]: http://oreilly.com/catalog/9780596805531
 [5]: http://www.amazon.com/Object-Oriented-JavaScript-high-quality-applications-libraries/dp/1847194141
 [6]: http://www.yuiblog.com/blog/2007/01/24/video-crockford-tjpl/
 [7]: http://developer.yahoo.com/yui/theater/