I am a ACTION Certified Personal Trainer. Aside from the obvious convenience of being an affordable education for those on a low budget ACTION offers a GREAT academic foundation in the basics of personal training and exercise science and it is VERY COMPREHENSIVE for an introduction. While the ebook is free, I strongly recommend going with the pro plan if you are a beginner as you will get a lot of additional help from the flash cards, actual online classes, practice exams, etc. Plus the staff are VERY friendly and hospitable.
As for the free exam. Don’t let the price fool you, the exam is a lot tougher than you would expect and it really focuses on the practical aspects of the personal training job and not just reciting math equations and so forth. The free exam is 100 questions and you get an hour and a half to repeat it.
Another thing I would suggest is to order ACTIONs study videos. It really helps and for $15 you get around 15 hours worth of video instruction on not just theory but practical applications and exercise technique demonstrations if you are new and don’t know a lot of exercises or its proper form yet.