A comprehensive introduction to network flows that brings together the classic and the contemporary aspects of the field, and provides an integrative view of theory, algorithms, and applications.
This book was the basis of one of my comprehensive exams for a PhD program. There is much emphasis on implementation: lots of discussion of data structures, etc. In my case we didn't need to know about data structures but did need all the algorithms, which the book does a good job of laying out, explaining, demonstrating. Can be long-winded, making it a little painful to read cover to cover.
As a beginner who just starts learning about data structure, I found this book not too hard to understand though I needed some time to review the basics before dwelling myself to the content.