This booklet is intended as a guide for beginning graduate students in Earth System Science.  It provides information on questions that will be important for a new arrival, outlines department procedures and policies, and gives requirements for the Ph.D. degree in Earth System Science.  It is neither an exhaustive compilation nor an official statement of requirements.  The UCI General Catalogue and Student Handbook should also be consulted.  Our intention is to update this booklet at regular intervals, so suggestions for additions and changes are welcome.