Some organizations are fortunate enough to have an on-site training person or staff. In that case, the selection of whom to choose to continue your mission is greatly simplified. More likely than not the person who will pick up where your training left off will be a rank-and-file staff member. Therefore, it is important those chosen for this role be seen as a leader to their peers. They should be well respected and experienced in the topics they will be covering. Mid-level managers are often good choices, but it is not wise for the "big boss" of a department or organization to be the trainer. Staff will feel intimidated and not free to express themselves if their boss is conducting the training. The trainer(s) also should have an outgoing personality, be accessible and willing to take on the role. An unhappy or unwilling trainer is doomed to failure.
Before you can cover subject matter in depth, you should train the trainer on some of the basics of effective training. These should include pointers on presentation, how to set up a room for effective training, the use of visual aids, etc. The more the trainer knows, the more effective he or she will be in delivering a message.
With this groundwork laid, you can begin to explore the topics that this in-house trainer will cover. A train-the-trainer session should have the look and feel of a coaching session. It should not be rushed and the trainee should feel free to ask as many questions as necessary to ensure understanding. Let the trainers know that you will be available to them and provide them with direct contact information in order to answer any questions they may have.
A few other things of which to to remind your newly-minted trainer:
-- They should always present themselves as the authority. A room full of professionals gathered for a training session can smell fear. You are the expert, at least for the moment, and you should conduct yourself as such.
-- In every training situation, there will be at least one person who thinks it is their job to make your life difficult. I label them the "untrainables". Dealing with these difficult participants effectively will garner great respect for your abilities from other participants. Do not let them dominate a conversation or agitate you. Just smile, say something like, "Good point, Bob," and move on.
-- Have fun! The best way to teach people something new is to "trick" them into thinking they're having a good time. Show passion for the material and enjoy yourself. The enthusiasm will be contagious.