How do I use branching to separate project into two "paths"?

I have a project that I would like to separate into two paths.  I want the end user to be able to select their path and then navigate through the project. The slides they see will depend on which option they've selected. 

How do I use the branching view to separate my project into two simple paths? 

Also, When I try to add more than 3 slides to a group in the branching window the option to expand/collapse/remove slides is grayed out, does anyone know why this is? How do I add and remove slides in a group after I've created the group? 

If anyone has any helpful links that explain branching view please let me know.