for more information on how to navigate using a topo map:
Step 1: What do you need
A wealth of map resources exist online but a map printed from and online source may not include all the necessary information.
A good source for paper maps is the US Geological Survey (USGS) http://topomaps.usgs.gov/
Step 2: Map name
Step 3: Scale
1:250000 – each map unit = 250,000 units on the ground
(i.e. 1 in = 250,000 in = about 4 mi)