If you are interested to give the Doctype Maven Plugin a try, then

1. Start with the New User's Tour and have a look at Create a new Doctype Model – this will create a new project ready to add your descriptors for your add-on
2. Have a look at the projectdoc Model Descriptors – this will help you understand the configuration options
3. Checkout model projects on Bitbucket – see how things work
4. Get familiar with Prerequisites and Project Settings – understanding these will make your configuration life easier
5. Learn about Patching – to know how to work around limitations imposed by the plugin
6. Understand use cases with Usage