Wallpaper and Wallcoverings - Using Maps as Wallpaper

We have built a new "old" barn in Colorado, located on 35 acres that borders the San Juan Nati'l Forest. In the guest room we want to cover one large wall in National Forest maps, the same maps that we and our guests use when we hike and backpack. I've never used a map as wallpaper and wanted to know if anyone has a step-by-step procedure on how to apply these maps to the wall. FYI, we'll be using maps that overlap by a Section. Will is be OK to overlap, or do we need to trim the maps exactly and have no overlapping? Also, after the maps have been applied to the wall, is there any product on the market that we can use to seal the maps without yellowing them? Any info will be most appreciated.

Trim off the borders and adhere to wall that has been primed with wallpaper sizing juast as you would do with wallpaper. Seal with a couple coats of clear shellac, which does not amber as it ages, or tinted shellac if you would like for the maps to look old. Shellac is smelly, so you might want to wait until spring when you can open windows and turn on some fans to exhaust fumes.