>This is probably a dumb question but where is mmMessageBox? It's obviously not like MessageBox where I can just call from a form. I couldn't find that info in the doc too.

Stephen,
Sure you can, as long as you have the appropriate references in your code. If you have:

using OakLeaf.MM.Main.Windows.Forms;

as one of your references.
mmMessageBox is a static class and you can call it in your code anywhere you want.

HTH.