The rapid increase in capabilities at neutron and x-ray scattering sources has resulted in a wealth of highly accurate data on liquids, allowing for the testing of sophisticated models pertinent to the microscopic dynamics. This book, written with the experimentalist in the field of liquids in mind, is a practical guide on how to infer the maximum amount of information from the data using a minimum number of parameters, employing a fail-safe framework that ensures that pitfalls are avoided and that small differences between various liquids can be uncovered. Also, it details excitations for a range of liquids, covering simple fluids, colloids, mixtures, metals and superfluids. Results are interpreted in words rather than in equations, bringing to the fore new links between these fluids and between spontaneous fluctuations involving thousands of atoms down to those involving just a few. By providing a review of scattering results in the field of liquids, and placing various liquids in context, the book gives an overview for the graduate student and the postdoc entering the field, and a refresher course, based on modern results, for established experimentalists. Moreover, in re-establishing the connection between the large-scale properties of liquids, and their underlying collision sequences, the book directly ties experimental results to the most important open questions in the field. It is hoped that the book will inspire theorists to take up the challenges it poses.