Here is a tutorial on adding a Facebook Like box (formerly a Fan box) to Blogger/blogspot. It’s a good way to promote your Facebook page. A Like box lets your readers:

• See how many users already Liked your page.
• Like your Facebook page with just one click, without having to visit the page.
• Read your page’s recent posts (if you choose to display them).

Now let’s proceed shall we?

I) Get your Facebook page ID URL

1. Visit Facebook and go to your page.
   
   
   

Copy the URL from your browser’s address bar. Trim the URL until you get something like this: 
http://www.facebook.com/IrfanDoggar1

http://www.facebook.com/pages/IrfanDogggar1/115496238467364 

II) Configure your Like box

1. Go to Facebook Like box configuration page (opens in a new tab/window). You will see a configuration box, like this
   
   
   
2. Now paste your page URL inside the Facebook Page URL text box.
3. Set other parameters such as width, height and stream. The Preview on the right will update itself as you enter the changes.
4. Click Get Code button when done. You’ll be given two codes, titled iframeand XFBML. You only need the iframe code.
5. The iframe code should look more or less like this

Copy the code (the code provided by Facebook, not the sample code in no.5).

1. In Blogger, go to Layout and click a Add-A-Gadget link. Select HTML/Javascript gadget and paste the code in the content box.
2. Save and view your blog.
3. Enjoy!