What am I supposed to be doing on Google plus?

I have recently activated my Google plus account through blogger. I have been posting and sharing things from my blog on Google plus, but not really sure what I am suppose to be doing.

Is anyone out there a big fan of Google plus and can give me a few tips as to what is happening over there?

A few questions I have:

1. How is it different from other social media, like Facebook or Twitter?

2. Is it just another platform to post material like Reddit etc?

3. Who should I add to circles, or should I bother?

4. Is there particular hashtag system or searching ability?

5. Should I bother?

Really appreciate any comments or private messages on dailyvowelmovements at gmail dot com

Thanks