Take a dive into creating your first Visual Studio Team Services extension by Niel Zeeman.
Niel covers some of the tools that are being used, the importance of the manifest and some of the APIs, to get you started in creating your first extension.
Niel uses the VS Team Services Extension project template, created by Josh Garverick, which supplies you with everything you need to create an extension. You can check out Josh's C9 demo video here. You can download the extension template from the Visual Studio Gallery or installing it directly from Visual Studio via Tools > Extensions and Updates.
If you have any questions/comments, please reach out to Niel by leaving your comment below or via the contact details in the video.