maydayp: it contains both the original Pharaoh, and it's expansion, Cleopatra. In that it has extra maps, and new buildings. Otherwise, I don't know if it has new custom maps, but they are easy to find, as there is a site dedicated to city builders, and hosts maps for the game.
http://www.gog.com/en/forum/pharaoh_cleopatra/custom_made_maps
to quote myself,
hey, for those interested, there is already a shit load of custom made maps, by other pharaoh players, like us.
http://pharaoh.heavengames.com/downloads/index.php
some of them are pretty cool, I've put a few up myself. "