The field of topography is a branch of geography that studies the natural and manmade features of terrain. Topographic maps take all of the details that make up a three-dimensional landscape and represent them on a flat, two-dimensional piece of paper or a three-dimensional raised relief map.
Here are some videos about topographic maps on YouTube:
Mr. Hayes’ 8th grade science class
An old US Army training film on how to read topo maps
Topo basics with illustrations from an old USAF Survival Manual
Here are a couple of online tutorials about topographic maps:
Bowling Green State University (an interactive tutorial)
Geospatial Training and Analysis Cooperative (includes field exercises)
Additional Links:
Topo Map Reading Tips for Hikers (simple tips for beginners)
Gallery of Virtual Topography (great examples of 3D topo maps!)
Topographic Map Symbol Key (downloadable PDF from the USGS)