The version I reviewed has informative material, but its presentation tells me that you should wait for the next version. PEM falls short of meeting reasonable standards for its own internal quality. For starters, every display page contains spelling and grammar errors. Examples of the passive voice abound on every page. Flawed language aside, several of the disk's pages suffer from errors and poor design.
Graphics embedded in pages include a few errors of their own.
For example, the text refers to a table for multiplication, but the drawing shows interrelations among international standards organizations. A page devoted to dielectric absorption is missing its accompanying drawing. PEM has several operational inconsistencies. PEM's topical coverage appears well centered on its intended market, but the program needs considerable polishing before I can recommend it. Wait for a later release and, in the meantime, hire the best instructors you can find to conduct a traditional training course.