The best place to find a timeline for Hernando de Soto is http://www.preceden.com/timelines/49606-hernando-de-soto. This traces his life from his birth in Spain to his death along the banks of the Mississippi River.
The timeline on this website provides many important points in de Soto's life, including when he sailed to the New World, when he led an expedition up the coast of the Yucatan Peninsula, when he became the first European to see Hot Springs, Ark., and when he reached the Mississippi River.
Another good timeline is found at http://www.timetoast.com/timelines/hernando-de-soto--8. It contains much of the same information but also includes information on de Soto's conquests of Nicaragua and Peru.