Schaum’s outlines were recommended above. I don’t know about Schaum’s outlines for engineering courses specifically, but I will say that their outlines for a number of mathematics courses are really valuable. As a student, I tended to look down on them as the Cliffs’ Notes equivalent for college courses. They are not. I did not really discover this until I was a grad student, teaching complex variable theory to undergrads. The best aspect is the large number of problems. If a student really works them, and does not leap ahead to look at the solutions, he/she will learn a lot.