You cannot teach people how to manage projects! It is a skill learned through experience. It is however a lot easier to learn those skills if you have received training in the techniques of project management as part of the experience period.
No amount of theoretical training can get the putative project manager to realise just how much circumstance and people will act and conspire to thwart project deadlines and budgets. Detailed documentation of project activity will merely act as an aide memoir as you sift through the ashes of a failed project.
A project manager should serve as an "apprentice" under the tutelage of a master project manager. In that way the novice can learn, aided by supplemental formal training, how to manage, and react to, people, resources and events whilst under the protective guidance of the master. A lot of the gain is learning how to react when things go wrong. The other important challenge is learning how to really communicate with people involved in or affected by the Project.