If you have a blog website and allow people to follow your daily post, you can do this two simple way.
1 . You put your RSS feed of your blog visible to visitors can click on and subscribe to it.
2. Using Google Feedburner widget.
I use this free plugin on my website to get subscribers to my blog.
Feedburner Email Widget By WyriHaximus
Feedburner Email Widget allows you to add a Feedburner Email Subscription widget to one of your sidebars.
More info visit plugin site at wordpress.org
How to enable Feedburner service for your blog?
To enable Feedburner follow these steps:
Go to http://feedburner.google.com and login
Click “My Feeds” in the upper-left-hand corner.
Select your feed from the list
Click the “Publicize” tab
Click “Email Subscriptions” on the left
Make sure “Feedburner” is selected, and click “Activate”
You can also Copy the HTML code in the box