Web development is such a large topic we can only scratch the surface, but we will post relevant and useful links and information here that we believe you could benefit from. This is just a start...
Web Developer Firefox Add-On and other web development add-ons
This Web Developer app belongs in the arsenal of every serious web developer and is one of our most-used tools. It is an extension for FireFox that adds a variety of developer tools to the FireFox browser. Identify and view CSS on any page, view and clear cookies, and many more features. See more Firefox add-ons for web developers at addons.mozilla.org/en-US/firefox/extensions/web-development.
Other Firefox Add-Ons
There are so many useful Add-Ons for Firefox, not only developers but most people will find something useful in the collection at addons.mozilla.org/en-US/firefox.
Google Analaytics API
Google provides some awesome tools for developers, one that we've been exploring is the Analytics API Data Explorer at code.google.com/apis/analytics/docs/gdata/gdataExplorer.html.