Improved drilling technologies and interest in unconventional resources combine to inspire drilling activity that, increasingly, brings petroleum geologists into contact with rocks that have been dramatically altered by diagenesis. The papers assembled here are about those diagenetic processes that most significantly affect porosity and other petrophysical properties in sandstones. Papers were chosen with the aim of giving readers who are unfamiliar with the field of diagenesis a quick primer on basic concepts that are widely applied today in reservoir quality assessment.