From BlenderWiki

Scripts Development

API

• API Introduction by Campbell (with examples)
• API Overview by Campbell (background information about how the api fits in)
• Dynamic creation of operators
• API reference

How to develop addons

• To start developing an addon, read these the coding guidelines
• If you need to have a look at some code snippets, please have a look at the Scripts Cookbook

How to distribute addons in Blender

Once your addon is ready, if you want to get your addon distributed with Blender, please follow the addons submission guidelines.
There, we explain the workflow to get a review, and to have access to the official addons repository.

Useful informations

Scripts Folder structure

These are the folders currently inside .blender\scripts:

addons	Contains Add-Ons scripts that aren't enabled by default. These have to be enabled in the Preferences panel.
modules	Python script modules.
presets	Python Presets for Blender, cloth, render, sss & sunsky so far!
startup	Scripts registered at Blender startup. Subfolders: bl_operators: Blender operators modules. bl_ui: User interface properties & window properties scripts.
templates	Script templates found in the text editor.

Tools

• Video tutorial: Writing Python scripts for Blender with Intellij IDEA