Some things to remember when writing Chrome extensions (Part 1):

I recently built a chrome extension. It maps craigslist housing searches onto a map. This is a two part blog post on a few things I’ll keep in mind when writing more Chrome extensions. This is the first post and will talk about parts of a chrome extension and where to put code. Of course the official documentation probably does a better job, but this summary is as much for me as it is for you.

Each Chrome extension has the following files:
manifest.js: This file will contain basic but important information about the extension, such as it’s name, description, any files being included, websites when the extension will come alive, as well as be able to make cross-site requests, as well as security considerations.
background.js: This file is your grand daddy. It orchestrates communication between the different parts of the system.
Other JavaScript files: These files represent what will happen inside different content views – page actions, browser actions, tabs etc.

Code organization:
background.js – Anything that the browser does, such as opening new tabs, placing buttons, assigning action to a browser button and so on, is handled by background.js.
some_content_script.js – You guessed it! Things that happen inside the content of a window – basically whatever happens inside the html tags is handled by some content js.