Solicit input from participants for class discussion of groups they are interested in. Very interested in learning. Some will have computer experience, but many have never used one.
Some seniors have difficulty handling a mouse.
Explain that there are other kinds of mice that are easier to handle. And that the font size on their browser screen is adjustable. Think of analogies and examples from their lives. Communicating with family and locating old friends is very important to seniors. Spend some time showing them 'people search' tools and how to use e-mail.