Examples of how to conduct complex battles (detailed turn by turn). Everyone must read this!

Can anyone tell me how to determine the level of a treasure hoard (with dwarves, preserves, etc.) in a town or fortress? I've heard that you can tell if there's only one stack of upgraded units guarding the treasure. How does the tactic for capturing treasure hoards and preserves differ in different locations? What is the probability of them appearing (maximum, single, etc.) on grass, snow, lava, etc.?
Please provide detailed information or a link!