The thesis is the result of a bachelor research project about Google's PageRank. An analysis of the hyperlink structure of the World Wide Web is made and a model for web surfing studied. Based on this model, some standard methods to compute the PageRank of web pages is investigated. Special attention is given to computing PageRanks by using linear systems. In this respect the IDR(s) method is applied to achieve an efficient computation. Several numerical experiments are performed in order to compare the efficiency of different methods in computing PageRanks.