notification feature

Earlier I asked for assistance to develop a notification function on a website.  I received great tutorials but it's not for what I am trying to do.  

 

I'd like to build in a feature that will provide a small bell similar to the one on this website and on Facebook and that will provide a count telling user that they have notifications.  It's a private web portal. Do you know of any tutorials or websites that can get me started? 

 

Thank you.