What is your precise goal with it?
Let's avoid basics and get deep! I'll go first:
I'm presently not doing much, hence this group! I aim to take part in groups related to my various niches (ESL in China and content marketing). My plan is to provide as much advice as I can, ask some questions and occasionally post a relevant link to my sites.
My goal with Google+ is to increase the conversion ratio for social traffic (conversion goal set in Google Analytics) for my two businesses. An equally important goal is to make some nice connections with pleasant people.
How about you?