The nice thing about Open Office Draw (besides it being free) is that it doesn't take long to learn to use it.
Below are a couple other tutorials of mine that are a good bit shorter and simpler than Nathan's.
Open Office Draw basic functionality: https://www.youtube.com/watch?v=DFUPmNJomrU
Open Office Draw for making certification maps: https://www.youtube.com/watch?v=TjDtIoT-Yv4