The study of the effects of disorder in electronic systems is an area of research that not only has a rich history but is also of deep contemporary relevance. In particular, these studies unraveled the very interesting phenomenon of Anderson localization wherein in low dimensions, all electronic states gets localized under the influence of arbitrarily small amount of impurities. This talk takes us on a guided tour of Anderson localization: Starting from the development of a phenomenological scaling theory, we will track the major mile-stones in the development of this field. As a way-point in our tour we will briefly discuss the extended classification scheme developed by Altland and Zirnbauer. This scheme classifies the disordered Hamiltonians in a ten-fold way on the basis of its underlying symmetries, thus completely specifying the low energy properties in each of these classes. Our tour culminates with a brief look at the low energy properties of graphene in the presence of vacancies (holes). We will show that graphene with vacancies is very unique and does not readily fall into the general classification scheme of Altland and Zirnbauer.