Industrial computed tomography for advanced industrial non-destructive evaluation is a complex technological area, encompassing nuclear radiation detectors, mechanical engineering, computational mathematics and radiation physics. Additionally, the cost of applying this technology may be prohibitive. This guidebook provides an introduction to gamma computed tomography for non-destructive evaluation imaging in the simplest configuration. It is intended to be of use to the non-destructive testing community, currently practicing conventional radiography techniques. It provides clear information on the relevant practical issues and problems related to setting up computed tomography for industrial non-destructive testing and establishes a basis for understanding the intricacies of the technology