You can now show off the number of people in your Google-plus circles, with the help of the Google Plus Widget. The widget also allows you to show the visitors of your blog that you have a Google+ account. Therefore it's a great opportunity to get in touch with your visitors!
How To Get Started
Go to: http://widgetsplus.com/
Click on the "Get Widget" button
The "Settings" page will appear.
Enter your Google Plus ID in the "Google +ID" box.
Adjust the "Widget width" to the size you want
Scroll up and click the "Get Code" button.
Your code will appear, copy it.
Login to your Blogger blog, go to "Design/Layout" and click on "Add a Gadget" on your sidebar.
Save it and view your blog.
Note: If the size is not okay, feel free to adjust it.
Don't know how to get your Google Plus ID?
Go to : plus.google.com
Click on your Profile Picture.
Copy the URL from your browser address bar.
The URL should be something like: http://plus.google.com/100475476355251995300
Your ID is the string of number e.g "100475476355251995300" from the URL above.
I hope this helps....