I learned to read and make topographic maps in my physical geology class at the University of Southern IN and in my Historical Geology Class at Purdue University. But you don't have to go to college to learn to read a topo map.
Imagine a lake bottom and fill the lake basin with water to the maximum. Now drop the water level 5 ft lower and trace the outline of the lake. Viewed from above you have your 5ft contour line now. Drop the lake level another 5 ft and draw the outline of the shoreline one more time. Now you have the 10ft contour level. Repeat until all the water in the lake is less than 5ft deep at the deepest part of the lake. If any islands pop out of the lake then trace the outline of the island as you drop the water level. When you view the finished map from above you will have a top map of your lake with 5 ft interval contour lines.
Most modern topo maps were made by taking two pictures of an area from an airplane and then using stereoscopic methods they draw the contour lines to make a topo map of that area.
You can learn more about topo maps and how to read them by doing a google search on "topographic maps".
Regards,
Moose1am
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