Andrew Sanders 
Introduction to Unreal Engine 4 [PDF ebook] 

This book serves as an introduction to the level design process in Unreal Engine 4. By working with a number of different components within the Unreal Editor, readers will learn to create levels using BSPs, create custom materials, create custom Blueprints complete with events, import objects, create particle effects, create sound effects and combine them to create a complete playable game level. The book is designed to work step by step at the beginning of each chapter, then allow the reader to complete similar tasks on their own to show an understanding of the content. A companion website with project files and additional information is included.