- Tell the Firefox extension manager where your extension code is. To do this, you need a text file which contains the path to your development folder. e.g. In *nix, your firefox extension folder will be /usr/account_name/.mozilla/firefox/your_profile_folder/extensions/ You need a file there, and inside the file you have a path pointing to your extension code (i.e. your development folder). The extension manager will scan the firefox extension folder and load your stuff in the development folder. (make sure the id is unique in the install.rdf file, and the min/max version match your firefox environment, e.g. >firefox3.5)
- During development, consider using separate profile, and turn on the debug/logging option inside firefox.
Practice makes perfect. Read through this example several times.
At last, you will need the Reference API (how to create a button etc...)