How to Turn a WordPress Site Into an Email Newsletter

1. Go to feedburner.google.com/ to set up a FeedBurner account. To do this, you will need a Google account -- if you do not have one, click the 'Create an account' button and fill out the forms you are presented with. When you are done, go to the FeedBurner site and log in.
2. Burn your WordPress site's feed. Type your blog's feed URL into the 'Burn a feed right this instant' text field, right in the middle of the screen. This will usually be yoursite.com/feed/. Click 'Next' when you're done. This will allow the FeedBurner service to manage your blog's RSS feed, and give you access to their suite of additional services, including email subscriptions.

3. Fill out the text fields that appear. Give your feed a title, and choose which statistics you want Feedburner to track (if any). When you reach the page titled 'Your feed is ready for the world. Now What?' click 'Publicize' on the top menu bar, then click 'Email Subscriptions.'
4. Click 'Activate' on the form that appears. A page will appear giving you the code for the email sign-up form. Copy the code to the clipboard.
5. Log into your WordPress admin area. Click 'Pages,' then 'Add New.' Select the HTML editing mode, and paste the code into this page. This will be the front page for your site, and will allow your visitors to sign up for the newsletter. Call it 'Home' or something similar and add any other information you want. For example, you could encourage visitors to sign up, or tell them the benefits of the newsletter. Click 'Publish' when done.
6. Add another new page titled 'Back Issues,' and leave the page blank. Publish the page. This will become the new index page of the blog, with the email sign up page you created in the previous step serving as the blog's home page.
7. Click 'Settings' on the left menu bar, then 'Reading.' Next to 'Front page displays' click the 'A static page' radio button, then select your 'Home' from the 'Front Page' drop-down menu, and 'Back Issues' from the 'Posts page' drop-down. Click 'Save Changes' when done. Your blog homepage will now display a form allowing people to enter their emails and receive your newsletter. Any new post will be automatically emailed to all your subscribers. If you want them to have access to your previous newsletters, place a link to your 'Back Issues' Page anywhere on your site.