C# writing files

Question

In a C# 2010 application I need to setup different directory levels in a file structure and place various files like pdf, word, excel, and tiff files in the various folders that are created.The full directory structure will look like the following:
D://totalinventory/department_codes/date formatted like mm-yyyy/quanity-on-hand/customer number.
Can you tell me how to write this code?