Integration with LinkedIn.

Hi,
I am new to integrate the social media linkedin in our ruby on rails
application.I registered the application in linkedin developer
website,but I don't know how to integrate that in our application using
authentication from scratch(without using devise). I used "gem linkedin"
and configured the api-key & secrete-key.Please any one help me to do
with step by step procedure.

Thanks in advance
Hemashree