A finding aid is a document that details information about an archival collection. It is used by individuals to assist them while using a collection during the course of their research. The information found in a finding aid can assist a researcher by providing information about a collection prior to physically engaging with a collection's materials. If you are looking for information in a collection, or across a series of collections, finding aids can assist you in identifying where in a collection an item might exist.
Finding aids for collections held by UC Merced, along with the finding aids for thousands of other collections held by libraries and organizations within California, can be found at the Online Archive of California.
An example finding aid, along with annotations describing a finding aid's various elements, can be found in Using Archives: A Guide to Effective Research.