Creating an Announcement
From the main Canvas course page, click the Announcements tab on the left side of the screen. When the page loads, click the button that says Make an announcement.
Give your announcement a title and body text. You may use the rich text editor to format the text or add content (i.e. pictures, equation) to the body.
Set your announcement preferences (as seen under the announcement's text box) and click the Save button when you are ready to publish your post.
The announcement will be sent, posted and should now appear in the Announcements tab in your course or under your home page under Announcements.