This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
For Oracle, DB2 and SQL Server DbVisualizer have built-in support for presenting explain plan data in a more readable style . For other databases you can run the appropriate commands that will generate the plan data and see the result in DbVisualizer.