Women wear dresses or shirts and tops, while men wear slacks and shirt.
Shorts are generally not acceptable for adults but are fine for the children. Some are pushing those boundaries, and it is certainly not a hard and fast rule. Men wear slacks more often than jeans, although jeans are acceptable, just as button down shirts are more prevalent than T-shirts. You should probably take along at least two pair of comfortable shoes with closed toe. Athletic or tennis shoes are well accepted, yet you might not want to bring your best pair since they will get dirty.