What's the best way to understand NYC subways?
Get familiar with the menus. I'd recommend sour dough bread, very good. ;) On a serious note, get a map of the subway system.
Map of subway system and plenty of patience.Try google.
The best way to understand the New York City sub way is to get to know the maps and subway signals. Once you learn how to read them, then chances of getting lost are minimal. For instructions, check http://www.ehow.com/search.html?s=how+to+understand+NYC+subways&skin=money&t=all.