What does your program do that needs to be documented? What types of records are created in your program? What are your mission critical records? What records document your decisions or are part of the audit trail? Examples might include permit files, project files, reports, publications, time cards, personnel files, contact files, and so on.
Look at each type of record and decide why it is created and maintained. Your program may be required to create and maintain records for a number of valid reasons including program agency, management reporting, statute, federal regulation, Agency policy or procedures.
Reference and personal convenience are valid reasons too. Frequently the only justifications for maintaining files are personal ones such as "I need the records for reference", "Joe wanted me to keep a copy," "somebody may ask for it", and "I don't trust anyone else to keep it." You will find that many of the series on the list for your office are working files, files maintained simply for convenience, or reference materials.
Put those aside for now, and concentrate on the files that directly support the Agency mission or agency. These are your "corporate" records. without which your program could not function. They are the ones you need to control.
Identifying the list of corporate or mission critical records is the most important and the most difficult step in the process. It takes a little time, but the benefits are great and it will allow you to manage your information assets much more effectively and efficiently.