I am in process of loading the Michigan TOPO Map and have selected the resolution setting to 1mi. Do I need to do this for each segment of the map when I load it? Can I leave the setting at say...15 miles and when I zoom in on my Garmin 60csx will it show the higher resolution detail or is it goverened by the resolution setting when I loaded it?
"Resolution" is not the correct term for what you are setting. This is usually called the "zoom level". It doesn't change anything on the map, but just determines how much you see on the screen. You can zoom in and out as much as you like on both the computer and GPS - set it wherever you like it.