What design patterns are typically used for Document Repository and workflow? [on hold]

I have to redo a c# Project involving documents scanning and workflow .There are many types of Documents involved along with features like OCR, indexing, storage etc. I am trying to research best practices and design patterns to incorporate. I envision the class structure as follows

Base Document --> Document A ---> OCR, Storage --> Document B---> OCR, Storage + Additional Business functionality
--> Document C---> Storage Only

I am learning design patterns so any help is appreciated.