This book focuses on the process of preparing raw data for analysis—commonly known as data cleaning. It covers a range of topics including data compilation, variable naming and labeling, data examination, and variable re-coding and transformations, among others. Author Bianca Manago discusses best practices for data preparation and analysis, emphasizing the importance of prioritizing transparency, best practices for writing script files, and file naming and organization. Two example projects and datasets are used to illustrate the methods in the book, and the datasets, script files, and output files in both R and Stata are available to download at https://github.com/biancamanago/DataPreparation_QASS2025.