Some pages take up more than one screen.
To move through a page, use the PageUp and PageDown keys on the right hand side of your keyboard. With the mouse you can also use the slide bar on the right edge of the screen. The tutorial looks best if it covers the full computer screen. Click on the button in the upper right corner of this window to make the display fill the entire screen. To move around in the tutorial from one screen to the next, use your mouse to center the pointer on the words next to one of the yellow buttons at the bottom of the screen.