You can post messages for your group in the group news page.
On the My Groups homepage, click the Modify News Headline button.
Click the announcement/news you want to view. You can add/edit/modify these news announcement in the modify news headlines topic of this help file.
To create a new headline, click the new headline button.
The Create New Headline page appears.
Type in the Title and Body fields, then click the Create Headline button.
To view an announcement, click on an announcement to open a new window with the text of the announcement on the group home page.