U.S. publications are shelved by Superintendent of Documents (SuDoc) numbers
Tutorial: Learning SuDocs Call Numbers
California publications are shelved by California Document (CalDoc) numbers
CSU Chico's guide to CalDoc numbers
Most other library material is shelved by Library of Congress (LC) numbers
In our area, this includes Gov reference and all of the Maps collections.
Tutorial: LC Easy (location TBD) at the workdesk/circ?
Use the Maps training binder for an introduction to map call numbers, locations and filing
Some of the material is also here (still under construction): Map Collection Call Numbers, Locations and Filing
