By A Web Design
To add module to your Joomla template, login to Joomla as administrator, by simply entering the url_of_your_website/administrator in your Browser. Enter the appropriate username and password {which was provided while installing Joomla} and then click on Login as shown in Diagram 1.

Diagram 1
After logging in as Joomla Admin, a Control Panel page opens as shown in Diagram 2. The Control Panel provides access to different Joomla functions and features.

Diagram 2
In the top menu, locate the link Extensions. Click on Extensions, from the drop down menu that appears click on Module Manager as shown in Diagram 3.

Diagram 3
The Module Manager page opens.
To create a new module in Joomla, click on New as shown in Diagram 4.

Diagram 4
There are 20 default modules provided by Joomla CMS. From the list of the modules click on Custom HTML which allows us to create your own HTML Module using editor as shown in Diagram 5.
NOTE: If desired you can create any module which you want to display on the frontend of website.

Diagram 5
You will see details of all module parameters that you will need to edit.
After all you’ve configured all the parameters as you desire, bind the module to a position in the Joomla template where you want it displayed. Create the Menu Assignment and then Enable it.

Diagram 6
Add the codespec of the module in Custom Output as shown in Diagram 7.

Diagram 7
Now you're done. Just click on Save/Apply, to make sure the changes are stored.
On the frontend of your website, you will be able to view the module at the specific position of your Joomla template as shown in Diagram 8.

Diagram 8
In the similar manner, you can add other modules to your Joomla template.