[A Google Scholar search for "random walks and electrical networks"][1] will bring up [a text by Doyle and Snell that is now available online][2]; for additional references check [the citations][3]. [1]: http://www.google.com/search?hl=en&q=%22random+walks+and+electrical+networks%22 [2]: http://arxiv.org/abs/math.PR/0001057 [3]: http://scholar.google.com/scholar?hl=en&lr=&cites=6936959390323618672