1. Click Here and Go linkwithin.
2. Look right bottom form there wrote Email, Blog link, Platform, Width etc (fill every information there). and click Get Widget.
3. Now Login your blogger ID. and when you see Add Page Element chose your blog site (If you have to many blog site). Now click Add widget.
4. Now your widget automatically add your blog site. If you want to see related post with image thumbnail view your blog site and see your posts below.
Note : If any problem please tell me with comment post