Dynamically expand a list and collect new information using the Create Column button on the List tab, Manage Views group. This takes you straight into the screen (2013) or dialog box (2010) to create your column.
You can also do this from the Datasheet view in 2013 by clicking the + symbol on the far right. In 2010, right-click on a column name and choose Add column. Think through how to grow your list and involve others who will use it to make sure the list stays functional.