For any retreat/home, assuming you have a map type personality, I would recommend that you have a copy, or three, of the USGS topographical maps at as large a scale as you can handle. These can be hung and overlayed with Mylar and marked up as need be with dry-erase markers or grease pencils.

The biggest issue with USGS maps is that they aren't updated very often so sections can benefit if you use Google-earth/map to update changes.

It is an interesting process that greatly increases the understanding and familiarity of the surrounding areas.

For areas not directly surrounding your retreat/s my preference id to get the Atlas/Gazetteer of your state. This is a cross between a topo map and road map that covers the state collected into a handy 16" by 11" format. These have far more detail as to the lay of the land (topography, vegetation, water and drainage) than any road map and have, based on those I have used, about 95% of what I need off a large scale topo map.

http://www.amazon.com/North-Carolina-Atlas-Gazetteer/dp/0899332773

Don't use the cover picture on the gazetteer as a guide. The picture on the cover of my Florida atlas/gazetteer shows a lower scale than what is inside.