can someone explain the differences between these different measurements?

Toe-In and Toe-Out.
This refers to the proper angle of your wheels from back to front.

Camber.
The outward or inward tilt at the top of your wheels.

Caster.
The forward or backward tilt of the steering axis.

Tracking.
When properly adjusted, front and rear wheels "track," or follow parallel paths, with each pair of wheels positioned an equal distance from the vehicle's centerline.

For more go to
www.midas.com
Hope this helps,
Tim

If you're really interested in Suspension geometry and tuning I highly recommend a new book by Don Alexander. It's called "High Performance Handling Handbook" It was published this year (2002) by MBI Publishing Company. It covers all the basics and then builds upon them by explaining advanced tuning for Street and AutoX/Road Track use. It mainly focuses on imports (good for us) but the material covered is pretty universal.