Spiral waves rotating in an excitable medium present a classical example of unusual nonlinear phenomena in distributed systems. In this paper we discuss the results of experimental studies of spiral wave dynamics in homogeneous excitable media which are modifications of the Belousov-Zhabotinsky system. A variety of dynamical regimes from very simple and well ordered to irregular complex ones are described that are created under different experimental conditions. Spiral wave dynamics is considered in stationary media with different excitability, under the influence of the boundary conditions, and under a periodic modulation of a parameter of the medium. The experimentally observed patterns are compared with the data of computer simulations on the basis of equations representing the properties of excitable media.