I'm finally on Google+. Here's a shortened link to my profile: http://gplus.to/jjhebert. I see Google+ as sort of a Facebook/Twitter combo. Instead of the "like" on Facebook, you have the +1 on Google+. Google+ and Twitter both have a "follow" option. Facebook has friends and lists and Google+ has "friends" as a circle and other default circles--with the option to create custom circles. Confused yet? There's the friends, family, acquaintances, and following circles. The idea here is separation and privacy. Each category has its own circle. You can choose to which circle you'll share information and posts. Each circle acts as a list too. Each user has his/her own profile, kind of like the Facebook wall, only no one seems to be able to post on a person's profile unless commenting or +1-ing something.
How does this post relate to self-publishing and book marketing and the overall topic of this blog ... how to publish books? Google+ matters because it's a new form of free online book marketing, and self-publishing a book should always include lots of social media for book marketing. Technically Google+ is a new "social network," but for you, Mr. or Miss Author, it's a way to put your book in front of some new faces. Go sign up at http://plus.google.com or I can send you a Google+ invite if you're unable to get in. It might be in invite-only stage right now (still). Not sure. Comment with your email if you want in.
On a side note, MindStir Media's website was recently updated with the +1 button for sharing purposes. I believe it's important to give folks sharing options. Some instructions if you want to add the button to your website: http://www.google.com/webmasters/+1/button/.