CircleCount.Com is a powerful service that lets you find shared circles, provides your Google+ community rank statistics, your circle & follower maps, recorded response on your G+ status updates and posts like +1s, comments etc.
The service is easy to use, simply visit its home page at CircleCount.Com, click the Login button and use your Google Plus account credentials for logging in. First time it will ask you to authorize its app on your G+ account using OAuth. After you allow the app access to your G+ account it will be directing you to Circle Count’s Welcome page showing you its features.
The service is very easy and userfriendly but still if you like you may have a look to its detailed video tutorial here.