Android Developer tools provides developers all the required tools and documentation for building and learning the application development after setting up the development environment.

One of the best tool provide by the SDK is doc (in the folder structure) or documentation in the SDK manager. if can download all the documentation related to any version of API for your help. Your can download all the documentation from SDK manager .

This documentation equipped with the developer.android.com site contents , you can get any kind of help regarding to the design and development when you are using internet or not after download this documentation.

Open any HTML page from doc folder in SDK and search about any topic in which you are facing any difficulties. you get all the information related to any method and classes.