For the 5 minute introduction, take a look at the GettingStarted page. For a more in depth introduction to WebDriver and various DesignPatterns that might be useful you may want to watch this GTAC presentation.
We release javadocs for the most recently released Java version of WebDriver. They are are available here.
MRToolkit provides a framework for building simple Map/Reduce jobs in just a few lines of code. You provide only the map and reduce logic, the framework does the rest. Or use one of the provided map or reduce tools, and write even less.
Map and reduce jobs are written in Ruby. MRToolkit was inspired by Google's Sawzall.