General
The network page displays a stream of posts and conversations, typically ordered by the most recently updated. This page is highly customizable.
Create a Post
At the top of the page there is a text box that says "Share". Clicking this box opens a new post editor. The post editor is customizable, but the basic editor provides fields for a post body and an optional post Title. Buttons below the text area to the left provide shortcuts to text formatting and inserting links, images, and other data into the post. The buttons to the right provide a post preview, the post permissions setting, and a Submit button to send the post.
Privacy Groups
The privacy groups you have created are displayed in the side panel. Selecting them filters posts to those created by channels in the chosen group.
Post Permissions
The access control list (ACL) is what you use to set who can see your new post. Pressing the ACL button beside the Submit button will display a dialog in which you can select what channels and/or privacy groups can see the post. You can also select who is explicitly denied access. For example, say you are planning a surprise party for a friend. You can send an invitation post to everyone in your Friends group except the friend you are surprising. In this case you "show" the Friends group but "don't show" that one person.