Lesson 4: Basics of ArcGIS Customization
In Lesson 4, we worked on building a start-up procedure that would ask the user for input (name) and return a message box, all upon starting up the .mxd document. An example of this is shown below:

Note the reordered toolbars with customized buttons in between the Table of Contents and the map window. It then returns the message:

The next procedure we worked on involved coding a calculator that would simply square whatever number the user input into a box prompting them for a number. This is shown below:

And the following is returned from the calculator:

The final procedure we learned about and coded involved the simple operation of changing a property in the Map Properties options dialog box. The option was changed from storing the full path names to the relative path names. This prevents ArcMap from having to store the entire path for every additional feature class and shapefile that is created, instead, it just stores the file name and the type of file it is.
This wasn't a very difficult exercise overall, the only parts that tripped me up were understanding some of the concepts with classes, inheritance and the various interfaces code. Reading through the exercise and the lectures again was helpful as well, but we were not expected to know what all of the code meant at this point in the semester for this project.