Usefull Mathematica Demonstrations (you can download the "Player" for free):
http://demonstrations.wolfram.com/TransitionMatricesOfMarkovChains
http://demonstrations.wolfram.com/FiniteStateDiscreteTimeMarkovChains
http://demonstrations.wolfram.com/ATwoStateDiscreteTimeMarkovChain
Other demonstration software:
Page of author of Orstat2000 software, Henk Tijms, has link to software download. (This was used in the first lecture for queue demonstration).
Other stuff:
Link to Yuval Nov's R course - has very useful lecture slides.