One of the biggest questions we get from new Mac users concerns the mouse. PC users are used to right clicking to get to the options menu but Apple mice look like they have one button.
That's just on the outside!
All Apple mice since 2005 have two buttons underneath the plastic cover. Here's the setup:
Under the cover are two sensors, one on either side of the scroll-ball. These mice are not set up to right-click automatically. Vist your system preferences and choose Mouse from the Hardware options (second row). You can choose what each button does- both are normally set to be "primary." Changing the right most to "secondary" will guarantee that every time you click on the right side it will bring up the right-click menu.
Newer operating systems may have a simpler options. If you are using your mouse left-handed, you may want to consider switching your primary and secondary functions
The Apple Magic Mouse is very similar. The sensors are still on either side of the mouse, but there's no longer a scroll-button. Instead, you can swipe down the center of the mouse to scroll- it's the same motion as scrolling an app on your iPhone! You can even go back a page by swiping left or right across the mouse with two fingers.
No matter which mouse you use, you can right-click to get the options menu. If your mouse isn't showing the right menu, check your system preferences and verify the settings. Enjoy!