Most of the "pleople" I've chatted with on G+ don't understand Google's scheme for friending, following and Circling on Google+. It's complex and counterintuitive, at least at first. But it's also important for users to understand how it works.
The question I'm going to answer here is: What makes another user's posts show up in your feeds?
Let's say there's a social networking fan named Jan Brady. She's on Twitter, Facebook and Google+.
On Twitter, you'll see Jan's posts if you follow her. On Twitter, it makes no difference whether she follows you back or not, you still get her posts if you follow her.
On Facebook, you can send a friend request to Jan. If Jan friends you back, you will see her posts in your News Feed. In other words, seeing Jan's posts requires both that you follow her and that she ALSO follows you back.
Google+ is different, and gives you more options.
To see posts by all the people you've Circled and only the people you've Circled, just click on the "Home" button at the top of the page. To see only posts by people in any given Circle, click on that Circle on the left.
But what the heck is that "Incoming" option?
At the left of your Google+ page, you'll see an item called "Incoming."What makes Jan Brady show up in your "Incoming" feed?
Jan's posts will appear in your "Incoming" feed if Jan has Circled you, but if you haven't Circled her back.
I hope this posts helps clarify friending, following and Circlng on Google+
(Note that this post was originally posted with errors. This is the corrected version. Thank you to the commenters who pointed out the errors!!)