You will first need to create your bulletin. For additional information on
creating bulletins 
Click Here

Highlight the text where you want to insert a hyperlink then click the Inset/Edit Link icon

Enter the URL that you desire to send the user to upon clicking the hyperlink. Select if you want to open the hyperlink in a new window or in the same window by choosing the appropriate Target option. Click the OK button to complete the action.

Save the bulletin when you are done.