Your home stream is where you see posts that other people have shared.
To fill your home stream with content that's most interesting to you, follow some profiles of other users or join some Communities.
You might also see recommended content.
Your home stream
You can see your home stream by choosing Home in the Google+ menu. The posts that you see in your home stream are based on relevance.
When you see a post in your home stream, you can:
Following people and Communities
You can find Communities to join based on your interests. When you join a Community, posts from that Community can show up in your home stream.
You can also follow people. When you follow a person, posts they share with you can show up in your home stream.
Someone you follow doesn't have to follow you back, so they might not see what you post.