This book describes the fundamentals of fluid mechanics phenomena for engineers and others. This book is designed to replace all introductory textbook(s) or instructor's notes for the fluid mechanics in undergraduate classes for engineering/science students but also for technical people. It is hoped that the book could be used as a reference book for people who have at least some basics knowledge of science areas such as calculus, physics, etc. This version is a PDF document. The website [http://www.potto.org/FM/fluidMechanics.pdf ] contains the book broken into sections, and also has LaTeX resources.