Forumlar / Cotonti / Extensions / [Request]Writing Extensions

Hey,

I would suggest to start reading all of the documentation that is available on the website here.

http://www.cotonti.com/docs/
http://www.cotonti.com/docs/ext/extensions/

Especially these are definitely recommended for developing:

http://www.cotonti.com/docs/ext/extensions/extdevguide
http://www.cotonti.com/docs/ext/extensions/xtemplate_programming

Another thing that is definitely good practice is browsing through other plugins' code.
Check out some plugins on GitHub and see how others do it. Guys like Trustmaster have a whole list of repositories on GitHub.

Good luck! :)