Use this geometry view test applet to become familiar with the geometry view navigation controls. The rule of thumb is that all navigation is done by shift-clicking and dragging, and that you're effectively grabbing a point in the world and moving it using the mouse. Think of sticking a thumbtack into the geometry and dragging around in some specific way. Here's a cheat sheet:

Shift-Click with the left mouse button and drag:

This lets you pan the viewport, i.e. translate it around inside the viewing window. It's like sliding a piece of paper around on your desk with your finger.

Shift-Click with the middle mouse button and drag:

This lets you rotate the viewport about the center of the window. Imagine sticking a thumbtack into the center of the viewing window and spinning the paper around it.

Shift-Click with the right mouse button and drag:

This lets you scale the viewport relative to the center of the screen. This doesn't have a very useful real-world analog, since you can't change the size of a piece of paper (except by cutting it!). But the point you clicked on follows the mouse. If you drag closer to the center of the screen, the view shrinks -- everything moves towards the center. If you drag away from the center, everything scales up.

I find this method of navigation to be very quick and intuitive. I hope you do too!