This will be a live document that gets updated as we continue to grow and learn. The basic pieces needed for your asset differ depending on what you are creating, but in theory, it should be as easy to deploy, import, or install as possible. The more you can provide guidance the better off your asset will be and people wont be bugging you for basic things.
We have provided import guides to help people learn how to do the basics, so you can reference those as well. Most assets such as workflow templates, form templates, custom actions, custom connectors, solutions, doc gen templates and user defined actions should contain a readme file as a txt or word document explaining how to use it. The asset should also contain the SharePoint list/library construct that it was built against. This does not have to have any content, but again the rule is to do whatever you can to help the user take the asset and use it, so sample data may help.