Hi Joni,
If Greg's link doesn't work here are a few depending on his interest:

Black's Catalog of Atlantic City Chips 2001 ed.
The Chip Rack (Nevada chips)8th ed. 2001
Official US Casino Price Guide 2nd ed. 2000
(This guide has lots of chip pictures)
Susong's Riverboat Price Guide 2nd ed.
(This one also has lots of pictures)

There are a few others concentrating in other areas of chip collecting, Indian, Illegal, Carribean, etc. I'm sure there's one or more that will fit his needs.