I highly recommend the series of Mechanical Engineering courses offered by Dr. Whiteman. The courses are self contained if taken in order, and all the theorems given are developed in the class, no formulas are thrown at you, so you can understand where the formulas come from and how to apply them. There are well developed and relevant examples in the lessons, often taken from real life engineering problems. And Dr. Whiteman does an excellent job in presentation, often with live demonstrations so you can get a better feel of the explanations. The courses provide a solid introduction to mechanical engineering, and even if you have taken some ME, these are a good review. What is presented in the courses are sufficient to understand most engineering designs. I have used what I learned here to study further engineering structures, for example, I am interested in the construction of Renaissance cathedrals, and applied what I learned to better understanding how they were built.