This article explains how to add an announcement to your Info Site, and how to "roll up" that announcement to the various constituency pages if you would like.
To add your announcement you'll need to get to the new announcement screen. This is different depending on if your Info Site has subsites beneath it, or if your info site stands alone. Follow the appropriate section below for your info site.
If your info site doesn't have subsites you'll see an "Add announcement to this site only" link in the lower right portion of your "Announcements" web part on your info site:
Just click on this link as shown in the red box in the image above. Then Proceed to the "Adding an Announcement" section below.
Then click on "View All Site Content":
Now locate the "Info Site Announcements" List in the "List" section of the page:
Now click "Add new announcement":
On the new announcement screen you'll see several fields. Each is described below.