Geocaching 101 taught you about the basics: Geocaching is a real-world, outdoor treasure hunting game using GPS-enabled devices. Participants navigate to a specific set of GPS coordinates and then attempt to find the geocache (container) hidden at that location.
The upper undergraduate classes (300 series) went into more details about all the cache types:
This is the original type of geocache and the most straightforward. These geocaches will be a container at the given coordinates. The size may vary, but at minimum, all of these geocaches will have a logbook. Larger containers may contain items for trade and trackables.
Mystery or Puzzle Caches
The "catch-all" of geocache types, this type may involve complicated puzzles that you will first need to solve to determine the correct coordinates. Mystery/Puzzle Caches often become the staging ground for new and unique geocaches that do not fit in another category.
These geocaches involve two or more locations, with the final location being a physical container with a logbook inside. There are many variations, but typically once you’re at the first stage, you will receive a clue to the whereabouts of the second stage. The second stage will have a clue for the third, and so on.
An EarthCache is a special geological location people can visit to learn about a unique feature of the Earth. EarthCache pages include a set of educational notes along with coordinates. Visitors to EarthCaches can see how our planet has been shaped by geological processes, how we manage its resources and how scientists gather evidence. Typically, to log an EarthCache, you will have to provide answers to questions by observing the geological location. For more information about EarthCaches visit http://www.earthcache.org/.
Letterboxing is another form of treasure hunting that uses clues instead of coordinates. In some cases, the letterbox owner has made their container both a letterbox and a geocache and posted its coordinates on Geocaching.com. These types of geocaches will contain a stamp that is meant to remain in the box and is used by letterboxers to record their visit. To read more about letterboxing, visit Letterboxing North America.
An Event Cache is a gathering of local geocachers or geocaching organizations. The Event Cache page specifies a time for the event and provides coordinates to its location. After the event has ended, it is archived.
Cache In Trash Out Event (CITO)
Cache In Trash Out is the environmental initiative supported by the geocaching community. The main aim of this program is to clean up and preserve the natural areas that we enjoy while geocaching. These events are larger gatherings of geocachers that focus on litter clean-up, removal of invasive species, planting trees and vegetation and trail building.
Wherigo is a toolset for creating and playing GPS-enabled adventures in the real world. By integrating a Wherigo experience, called a cartridge, with finding a geocache, the geocaching hunt can be an even richer experience. Among other uses, Wherigo allows geocachers to interact with physical and virtual elements such as objects or characters while still finding a physical geocache container. A Wherigo-enabled GPS device is required to play a cartridge. Learn more at Wherigo.com.
Geocaching 502 will test your ability to apply everything you've learned about geocaching so far. Combining all your knowledge, along with the required research project, will lead you to successfully pass the course by acquiring the final coordinates, finding the cache, and signing your name on the log. Below are several sources that will help get you started to solve the puzzle:
Once you pass this class you will graduate with high honors in "Geocaching Puzzle Solving"
I will tell you, your main tool to use in your research is Wikipedia. However it is REALLY important to understand how Wikipedia stays relevant as a valid research tool. It is even more import to realize that, while anyone can provide edits to any page, all edits are reviewed to ensure Wikipedia remains a valid document.