The KINDLE VERSIONS of the top three books below are PRINT REPLICA (instead of the old poor quality wrappingtext versions, which ruined the formatting). These new versions look exactly the same as the paperbacks. They're basically pdfs in kindle form. You can read them on your computer with the free kindle app.
If you are an instructor and would like to order a large number (say, at least 10) of any of the top three books on this page for a class you are teaching, just email me and we can work out a bulk order at a reduced price.

Special Relativity  For the Enthusiastic Beginner (David Morin)Selfpublished (so that I could keep the price low) through CreateSpace, 2017, 250 pages. Back cover (concise description of book) This book is a revised and expanded version of the last four chapters in my Introduction to Classical Mechanics, with Problems and Solutions textbook. A great deal of additional commentary has been included in order to make the book accessible to a wider audience. 

Probability  For the Enthusiastic Beginner (David Morin)Selfpublished (so that I could keep the price low) through CreateSpace, 2016, 370 pages. A set of exercises suitable for homework problems is located here: Exercises. The later chapters don't have as many, but more will be added in the future. Note 1: Although my other books deal with physics, there is no physics in this book. It's just a fun introduction to probability. 

Problems and Solutions in Introductory Mechanics (David Morin)Selfpublished (so that I could keep the price low) through CreateSpace, 2014, 350 pages. Note 1: I generated the book's material during the dozen times I've taught Harvard's introductory mechanics course (Physics 15a). 
Electricity and Magnetism, 3rd edition (Edward Purcell and David Morin)Cambridge University Press, 2013. 

Introduction to Classical Mechanics (David Morin)Cambridge University Press, 2008. 
Waves:The following files are a beginning draft of a Waves book designed for college sophomores. The Fourier and Interference chapters are a little more polished than the others. There will certainly be typos and things that I will change, but there's a lot of nice material here as it stands. There will also eventually be chapters on optics and water waves.1. Oscillations 2. Normal modes 3. Fourier analysis 4. Transverse waves 5. Longitudinal waves 6. Dispersion 7. 2D waves and other topics 8. Electromagnetic waves 9. Interference and diffraction 10. Intro to Quantum Mechanics 
Problem of the week: A set of (very hefty) problems, some of which appear in "Introduction to Classical Mechanics," is located here. Limericks: Many of the limericks in "Introduction to Classical Mechanics," along with ones on other topics, can be found with annotation here. More humor: If you like the limericks, here's some more physics humor. 
Contact: morin@physics.harvard.edu