Abstract: In this talk I will introduce basic methodologies used to establish statistical properties of deterministic dynamical systems (and also purely random ones). The talk is meant as a preparation for a second talk, and will be focusing on statistical aspects. In fact, I will try to minimize the dynamical systems parts as much as possible, and hope that the talk will be accessible to an audience having some basic knowledge of probability theory. In a follow-up talk I will illustrate in detail how to implement these methods for certain dynamical systems.