I wish to have the user make a choice in a select box and then in a Dymamic Action which waits for the select box to be changed it reads the select box value that was chosen
Create a Dynamic Action which fires on "Change". As a true action:
apex.item(this.triggeringElement).getValue()
This will get the value of the element which triggered the change event and will set it to the affected element you choose. Note though: the value of the select list will be the underlying return value (eg ID), NOT the display value.