It will surprise you how little of the material you might prepare will actually be used, so take care not to allocate too much of it.   I strongly recommend that you consider the following:

1. Plan for four sessions of one hour’s duration with plenty of discussion and down-time between.   The second and third sessions will be the most productive.
2. Insist that the event be catered, at least to some degree, and not just with sugary sweets.   Insist also that the mid-day be occupied by a lunch that all participants can go to, privately.
3. Set a list of no more than five “training objectives” for each session.   Each objective should be expressed as a single sentence.   Review the objectives at the beginning and at the end of the session, and present each objective in this way:
   • “This is what we are going to cover.”   If you have questions as we proceed, note them and we will cover them at the end of this section.
   • Cover it, at an even pace.
   • “This is what we have just covered.”
   • Kill time for about thirty seconds.   “Now may I take the first question, please?”   (If you ask, “any questions?”, the answer will be, “No.”)   Be inviting, and patient, and scan the entire room for questions.
4. At the end of the presentation, repeat once again the call for questions.   Be about five minutes early for the next session and repeat the call for questions – call for “the first question about” anything up to that point.
5. Wait until anyone completely finishes speaking, restate the question as you understood it (but in your own words), pause, and ask unhurriedly if you were correct.   If so, then answer the question, using the terminology that the asker used or carefully and clearly substituting the more appropriate terms.   If you do not have an immediate answer, carefully write it down and say that you will get an answer at the next break.   (It is helpful to have a “research assistant” in the room who can Google things for you and furnish you with the information sought while you continue.)
6. In a training session of this kind, terminology is the biggest potential boulder-in-the-road, especially since some folks will be coming to the seminar with different meanings for some of those words.   Therefore, the beginning of your first session might be to present a glossary of the most important terms.   Actually distribute this, go over it point by point, and remember to use 16-point type or larger.   Use ordinary vernacular, and take care that you do not merely substitute one “loaded word” for another.   Take care that your glossary is complete.   People will have it out on their desktops all day.   Notice if someone abruptly stops listening to you and starts looking at that piece of paper.   (Printing it on slightly beige colored stock helps you to see from a distance when they are studying that paper:   you know that you have briefly “lost them.”   Slow down.   Reconsider, on-the-fly, your most recent point, but do not call-out that person.   Do not negatively reinforce the behavior of people using the resource that you yourself have given them for that purpose.
7. Even if you are a co-worker with these people every single day, do not under-estimate your power as an instructor, nor the unacknowledged vulnerability inherent in being in a classroom setting, even “among friends.”   Don’t try to be a comic to relieve the tension.   Speak slowly and clearly.   Have water, but in a bottle that you can seal.   (Heh.)
8. Expect butterflies.   They will fly.   (Become worried only if you do not feel them.)

If you know who is going to be participating, try to spend a little time with each of them a couple of days ahead, show them your proposed outline and ask them about things they would particularly seek to know.   Note each person’s name next to the item on your outline, and when you begin and end this point, make a general gesture in their general direction without calling them out by name, and ask the wind ... “is that helpful?”

In a professional-training setting, do not quiz.   Unless you have been tasked to assure a particular competency that they are required to demonstrate (which is not the case here), do not put anyone on the spot.

(Ummm, yes.   I have been.   For many years.   Still am.)