Menus
Mouse users Left-click on a title in the menu bar, and the menu will drop down. Then click on the desired option.

Keyboard users Hold down the Alt key, and press the letter corresponding to the menu title. The appropriate letter is highlighted on the menu bar. When the menu drops down, either type the letter of the desired option, or move up or down with an arrow key until the option is highlighted, and press Enter.

The letter corresponding to an option is usually the first letter of the option name. This is not always so, however, because there are only so many unique first letters!