Once installed you need to configure the providers. See the below for tutorials regarding them (currently only provide tutorials for the major providers).
www.joomlapolis.com/forum/6-news-and-publicity/229505-configuring-cb-connect-7-x
Ensure your CB Login Module under Login and Logout Options is configured to load CB plugins by setting "CB Plugins integration" to "Yes". You should then see the sign in buttons in your CB Login Module if providers have been configured.
Now you simply click the sign in button to register a new account with your provider account details and login. To link an existing account you must login normally first then the button will link the two accounts allowing you to login with your provider account from then on.