gaussian books

Hello all,
 I am new to gaussian 98 and I was wondering if anyone
 could recommend a good reference book.  I found at the
 gaussian site the book:  Gaussian 98 User's Reference,
 Æleen Frisch, Michael Frisch for $50.  Is this book
 comprehensive - I mean does it describe both commands and
 calculations (equations, etc.)?  I know there is online
 help at the official site, but I would like a good
 reference book as well.  Thank you in advance to all who
 respond.  Have a great day.
 Don Keidel
 Donald J. Keidel
 University of California, Riverside
 Department of Biochemistry and
 Molecular Biology
 Riverside, CA 92521
 phone:  (909) 787-5493
 fax:  (909) 787-4434
 dkeidel397 { *at * }