I have taught a similar college course to potential contractors using a couple of different texts. One supplemental text that I used was from a series of texts known as the Parker/Ambrose series, particularly "Simplified Engineering for Architects and Builders" by James Ambrose.
Apparently you are not a structural engineer, and perhaps not an engineer at all. In either case, I offer you the same advice I gave to my students....
Structural Engineering cannot be learned from a single book nor can it be properly learned on one's own. It is a course of study, inclusive of the statics that GregLocock mentioned and continuing through a career of practical application and mentoring by others.
As I further told the students, "This course will not make structural engineers of you. It will give you insight as to the process that structural engineers go through in designing a building. At the end of the course, they understood what structural engineers do, including their liability, and I don't recall ever having a student change his major course of study to engineering as a result.
