If you have ever thought about building a Fx Extension, here is a comprehensive guide that can help you not just build an extension, but one that will get used.  The Developing a Firefox Extension That People Actually Use: 32 Essential Tools and Tutorials is very informative (but not overwhelming) with most of the steps containing external links.  The opening paragraph sums it up well.. Over the past few years, Mozilla Firefox has dramatically increased in popularity, largely because of its ability to incorporate extensions. The extensions developed for Firefox range from simple calculators to complete application replacement, and their…