Tessources is your friend. You'll want to search there for the Landscape textures (that should find it easy enough), the improved landscape normal maps from better landscape shadows in the distance to get rid of the nasty blocky look of them. I highly recommend also searching for the Advanced Water mod. I'd give the link but just don't have them bookmarked cause I searched em out and downloaded them, never bothering to bookmark em cause I archived them on a network drive after downloading and just didn't worry about it.
Another very good mod to add flavor and allow you to build a party of adventurers is Toaster Says Share, also found on tessource. This one made the game interesting enough for a THIRD run thru it now.