Is it illegal to reference Microsoft's product names (Excel and Word) with their trademark on my flyer?

I want to teach computer cles and would like to advertise that I teach Microsoft Excel, PowerPoint, Word and Outlook. I have looked at Microsoft's website and saw the trademark rules but I am still unclear. Is it just a matter of making sure I use the "R" symbol with the circle around it or do I have to get written permission from Microsoft?