Simply add Aweber forms to all posts/pages at bottom or top. Alternatively use a shortcode to add forms to your content.
You will find the settings under Settings -> Simple Aweber Integration in your WordPress admin panel.
For basic usage, you can also have a look at the http://www.schurpf.com/simple-aweber-integration/. To find help, pls read http://www.schurpf.com/simple-aweber-integration-help/.