Yes, once you get your base mesh detailed in Z you can also texture it there as Z doesnt use UV's as far as I am aware its straight into it. ZCentral should be able to help on the texturing front, as there are tutes out there for ZB2 to get you started.

Normal maps are basically a texture map of RGB light from the Hi Res Model and mapped onto the Low Res Model.

Mike McKinley has a free tute on Normal Maps in the vids section.