Infosec Resources has a free online tutorial, An Introduction to Fuzzing: Using fuzzers (SPIKE) to find vulnerabilities. While not directly related to microcontrollers, this resource provides a hands-on guide to using open source Linux tools to find vulnerabilities in code on a networked Windows machine.
To fully participate in this demo, you’ll need two machines on your own network: one target with Windows, one fuzzing system with Linux (BackTrack 4 Final or later recommended.)