Included in the Sitefinity 4.1 SDK is a new Visual Studio template. This template can be used to create a new Sitefinity 4.x Products module. Modify this sample module to create other types of Sitefinity modules.
This post below describes how to get started with this Visual Studio template:
Creating a new module with the Sitefinity Module Template
1. Open Visual Studio
2. Open your Sitefinity Project
3. Right-click the Solution and click Add –> Add New Project

4. Search for Sitefinity, select the Sitefinity Module template

5. Type the name & location for your new Sitefinity module and click the OK button
6. Click the Finish button

What now?
Module creation is a challenging topic right now. The Products Module, created by the template above, as been around for awhile. It’s also present in the SDK sample projects:

A lot of documentation, pertaining to this module, can be found here. However, this documentation is in the midst of being revised. If you have success modifying this template to create a custom module, please share your experiences with others.