Plugin Coding Tutorials?

Hello,

I’m not sure if this is the right place to post this but the description sounds fairly close to what I am looking for.

I would like to extend a wordpress installations functionality with a plugin/widget.

I have searched for a few days and have discovered that there currently is not a plugin which offers the functionality I desire (I am not surprised by this as I am looking for something that is very specific that I have never seen before.)

As such I would like to code a plugin/widget.

I have been searching for some information on coding plugins and widgets and have not found what I am looking for.

If someone could recommend a few tutorials I would be greatly appreciative. Even starting with a plugin that is basically a “hello world” example, so I can figure out the basic structures of packaging and deploying for word press.

Thank you.

E.