To include forms on a WordPress site, you need a plugin. One of the most popular plugins available is Gravity Forms, which is what this article describes. Once Gravity Forms is installed, you will see a new item in your admin menu labeled Forms.
To add or change the information governing how you are notified about a form, you need to open the form for editing and click the Notifications item from the top, horizontal menu (see Forms: Introduction for screenshots and information on opening a form to edit it).
There are many, elaborate notifications options (you can email different people depending on different things, etc.), but the basics are noted below: