You have two sides, one out in the field and one in. Each man that's in the side that's in goes out, and when he's out he comes in and the next man goes in until he's out. When they are all out, the side that's out comes in and the side thats been in goes out and tries to get those coming in, out.
The 12th man carries the drinks.
To find the cache complete the Wherigo cartridge found here (username and password is the same as you use on www.geocaching.com).