A group of kayakers and canoers, including a handful from the Gainesville area, are preparing this week to take on the state’s “Little Amazon” — the Altamaha River. On Saturday, about 350 paddlers from all over the nation will make the 105-mile journey from Baxley to Darien on the Altamaha during the eighth year of “Paddle Georgia,” an annual trip sponsored by the Georgia River Network. The trip will take seven days.