A few of my friends were asking me questions about Google+. Since they were all basically asking the same questions, I thought I would put together a blog post about the service, how to use it, and what it means for the future of Facebook.
What Are These Circles About?

Google plus is an application that allows you to share posts, pictures, videos, and links with people on your own terms. It is important to understand that while Google+ is different from Facebook, the concepts are not new. It's all about understanding the purpose of the software. On Facebook, you create and manage connections with your friends. On Google+ you create and manage audiences for the stuff you want to share. This is an important distinction to make. On Google+ you can add someone to your circles. And anything you post to that circle will be visible to them. It's a one way relationship, whereas Facebook is a two way relationship.
You can think of using Google+ as determining what you want to share with different groups of friends and then sharing it with them. A Circle is a list of people based on how you see them, not on how they see themselves. There have been quite a few people comparing Google Circles to Facebook Groups. However, I think these people are making a terrible comparison that serves to confuse people. Think of Circles like Facebook Lists. The Circles are how you organize your friends, acquaintances, family members, people you follow, etc.
About last night...
So lets say you have some embarassing photos of yourself acting completely obnoxious and out of hand at a bachelor party. It happens, you have a few too many drinks and next thing you know, you wake up in a strange room in Bangkok. Now you probably want to share these photos with the other three members of your wolfpack, but you don't want to share them with anyone else. Well never fear. Google+ to the rescue.
When you post anything on Google+(status, photos, videos, or links), you will see this underneath the "Share what's new" box:

Right now its set to send the post to my "Friends Circle." If you click on "Add more people," you will be able to add other Circles and even individual people that will be able to view your post. If you want to prevent someone from seeing the post just don't include their circle or their name.
Isn't that brilliant? Facebook's model starts with everything public. It's then up to you to restrict access to your posts. Google+ takes an opt-in approach as opposed to an opt-out one. With Google+ you specifically say which circles you want to share a piece of content with.
You can also manage these settings when you post photo albums. And the best part about Google+ is that even if you make a mistake and show a photo album to a circle you didn't intend to, you can change the audience after the fact. You can also edit posts after you've made them and control whether people can comment on your posts, or share them to their own stream:

Other Stuff
There are a few things that I need to cover, but don't deserve a whole lot of depth. Perhaps the best feature of Google+ is hangouts. I have a few friends that live across the country from me. They are all on Google+, so we can use the hangouts feature to have group chats. Its basically Skype on steroids for free. What is good about hangouts is that your friends can jump when they see you hanging out with other friends.
The Stream is the The News Feed. "+1" is Google+'s equivalent to the "Like" button. "Share" works like it does on Facebook, except that you can share pretty much anything. If you are familiar with Twitter think of sharing like retweeting. There is no equivalent to posting on someone's wall for Google+. The closest you could come would be to post to your own stream and have that person being the only one who can see it. However, if they haven't added you to a Circle, they won't see it unless they view their "Incoming" stream.
If you have an Android or iPhone, you can get the Google+ app which includes all sorts of features that you might find useful. I can't speak about those Apps because I haven't used them, but it's worth checking out.
What About Facebook?
Google+ has a lot of people talking about the demise of Facebook. The popular argument is, "Facebook took down Myspace. They can fall too." While that is true, Facebook is very established. I think that Google+ is the first legitimate competitor to Facebook. It's clean, simple design and focus on opt-in sharing are just the thing that many Facebook defectors are looking for. A lot of people are tired of Facebook's continuous privacy debacles. That coupled with the ill sentiment that many feel towards Facebook are why I think Google+ has a chance.
My prediction, however, is that both companies will battle it out for market share. The competition will make both products better and in the end we will see two social networks.
We are looking at the Apple/Microsoft rivalry of social networking. And this is just the beginning.