My site

1. Go To Blogger > Design > Edit HTML

2. Backup your template

3. Click Expand widgets templates box

4. Search for <data:post.body/>

5. and now if you wish to add the plugin just below your post titles then add the giant code below just above <data:post.body/> or if you wish that the plugin may appear at the end of your posts then paste the following code just below <data:post.body/>

<div id="fb-root"></div><script src="http://connect.facebook.net/en_US/all.js#xfbml=1"></script><fb:like href="" send="true" layout="button_count" width="450" show_faces="false" font=""></fb:like>

  6.  Hit save and you are done!