1. You must forgive those who are already experts in the field of web browsing, there you will find some platitudes. My first working idea is that "internet" is equally accessible to anyone with the technical means to log in and, therefore, I do not know even now which should be the level of literacy that potential readers must meet to read this article. So, I took the middle path, therefore, here you will find both the most important things and the ones that are more specialized. In any case, I tried to emphasize here the gateways, that is, those network sites that allow you to access other sites (a kind bibliography of bibliographies navigation).