This is not something new, and is not something complicated to make. This subcribe via email form can be used to facilitate the readers to get posts/articles of sites they love as they will be noticed via email just everytime a new post is published by sites they subcribed so they won't miss any posts to read. This service is powered by feedburner, http:// feeds. feedburner.com/, which is part of google. For bloggers there are two options to choose to add this service to the site, the first is by adding a new gadget through the gadget page and the second is by adding it through the official site. To add through the gadget page is simplier but you won't have any option to choose to display it on your site, while through the official site you'll be opted out if to display it as a anchor link or a complete form. Even you are permited to modify the view of this gadget as you'll be given the code to add it to your site manually.
Let's Go Everybody
To Add It Through The Gadget Page, You Can Make The Following Way
1. Go to your blogger dashboard.
2. Go to design page.
3. Click on element "Add Gadget" where you want to place the subscription form.
4. Just after you click element "Add Gadget" you'll be taken to the gadget page where you can select a gadget to add to your blog, just click a gadget named Email Subcription, or maybe that close to it, i forgot the name.
5. Specify the parameter as you want and save it.
To Add It Through The Official Site, You Can Make The Following Way
1. Go to http://feeds.feedburner.com.
2. You'll find a column located on top left, that right above it there's a notification like this: Burn Your Feed Right This Instant. Type your blog or feed address here. Just type in your blog address, check the I'm a podcaster box if your blog contains a lot of video and click next.
3. After, you'll find two columns which are for activating your feed. In the column titled Feed Title you may type any words as you want. And in the Feed Address fill with any word that you want it to be your feed address and then click next. Example: if you fill it with slametxxx, then your feed address/url will be http://feeds.feedburner.com/slametxxx.
Here, your feed is already active, and so you'll get a congratulation from feedburner for your success activating the service. But hold on, don't be glad here, cuz you're not done. You have to get the code to add to your blog to display your subscription form. And to get it, you have to follow the intruction below.
1. Go to your feedburner home page and click the Publicize button on top left.
2. After, find a thread titled Email Subscriptions on left side of the page and click it.
3. Now scroll to the bottomost layer and find a button titled Activate, which along with it is a notification says: This service is inactive. Just click the activate button.
4. Well after you'll be served with some options where you won't need any help of others to set it, like to decide whether you want to add it as a widget or get the code and add it manually to your blog.
5. Click save button in the bottom and you're done, now you can celebrate your success if you want to do so.