What are the list of documents that a Business Analyst needs to maintain?

As a Business Analyst, your BA life depends and revolves on the following documents (better known as Deliverable in the BA world):
BRD-Business Requirement Document
URD-User Requirement Document
FRD- Functional Requirement Document (Include non-functional documentation in this)

 These docs are labeled in several different acronyms even the PM doesn't know so don't worry about it. If you master your skills in these deliverable, you become the perfect BA as everything you do from here on, depends on what you present in this documents. This process is critical because before producing these docs, your elicitation process must be thorough.