"WordPress is an open source blog tool and publishing platform powered by PHP and MySQL. It's often customized into a Content Management System (CMS). It has many features including a plug-in architecture and a template system. WordPress is used by over 13% of the 1,000,000 biggest websites". Source: http://en.wikipedia.org/wiki/WordPress
For this section, we'll make the following assumptions:
We already have a working instance of WordPress (version 3.x)
Our phpList site is accessible through HTTP / HTTPS from our WordPress site
Download the latest version of Jesse Heap's phpList Integration plugin from http://wordpress.org/extend/plugins/phplist-form-integration/, unpack it, and upload the contents to your wp-content/plugins/
directory in WordPress.
Activate the plugin from within your WordPress dashboard:
Under the Settings menu, click on the new PHPlist link to configure the plugin...