For the hungry - seven-letter-placements (aka Bingos) are easier if you recycle the blanks, i.e. replace them on the board with a tile of the same letter from your rack, and then make your play. I partook once in a game in which the first five entries were bingos, and seven of the first nine, using that rule. Final score was roughly 595 to 398.

Regarding clocks: they're like chess clocks - two clocks actually, interconnected so that one starts when the other stops. Your clock runs while it's your turn, and then you push a button stopping yours and starting your opponent's. Not everyone uses them, especially in casual games.