One critical step that seems to be often skipped is lag bolting the ledger board to the house (see picture #2 above). This is important because the lag bolts carry not only most of the weight from your structure but all the weight that you put on it as well. Obviously you can't nail into brick but when attaching a ledger board to a house that isn't brick, relying solely on nails alone to hold the weight is going beyond what they are designed to do.