Tip: Show Hidden Items
Sometimes I have a need to see all the folders in the Finder, including the hidden ones the system uses. An easy way to do this is Command-Shift-. (that's a period) and it will show everything. Do it again to toggle it back off.
Be aware that you shouldn't generally muck around in those hidden folders, since the System puts its ugly but necessary junk in there. Kind of like the closets at PEBMAC World Headquarters. What, everyone doesn't have a vintage oscilloscope, a cookbook from 1808, and a Kundela tucked away somewhere?