To access the FreePBX modules, follow step #1 on this page:
The modules are listed along the left-hand side of the web interface, and are divided into two sections, "Setup" and "Tools." Once you're at a specific module's page, you can hover your mouse over the title of each entry and get instructions on what the entry does and how to configure it.
For an overview of the modules, click here:
For more details about each module, click on the name of the module, below.