How do I start to develop a Drupal 7 module that adds a new content type with some custom fields, so it generates all the output I want?
Although its possible to do programatically, your easiest bet would be to use features.
This is how you would do it:
- Manually create your content type
- Manually add fields
- Create a new feature and export the content type (and its fields)
Now if you install this feature is a fresh Drupal installation that content type and fields will be automatically added.