For a good overview of Thomas Bayes see the Wikipedia article on Bayes.
His main paper is "An essay towards solving a Problem in the Doctrine of Chances".
He is celebrated, not because he invented what is now known as Bayes rule (which was probably invented in its current generality by Pierre-SimonLaplace?), but because he had the idea of using probability to give the distribution over a parameter. This is the trick that makes BayesianStatistics? work.