ARD Tutorials

There are many resources out there to get you started with ARD and make it work for you in the lab or school.
I've listed a few below.

Video Tutorials from Apple
Easy Setup
Software Distribution
Remote Assistance
Remote Administration

Apple Remote Desktop 3 Administrators Guide

Online Webcasts
Using Automator, you can create multi-step actions that can perform repetitive tasks for you.  This requires 10.4 which supports Automator.
Automator Online Seminar available, 34 minutes, free
Workgroup Management Online Seminar, 34 minutes, free
Classroom Management Solution Webcast, registration required, free