If you want to get across a message during a classroom session you must have some visual aids for the trainees to look at. Simply standing there and talking will not work!
Visual aids cause the audience to focus on something even if they are very basic such as writing on a whiteboard. Some aids are better for some things that others. A video can show movement: maybe a forklift overturning, which the instructor cannot do.
A whiteboard or flip chart along with the appropriate pens can be used to conduct an entire course if necessary and models of forklift trucks can be used to illustrate various things during a classroom session.
The most common visual aid nowadays is Microsoft PowerPoint. Of all the Office programs PowerPoint is the easiest to learn and providing you have a computer, is without doubt the number one choice for all speakers nowadays.
A little tip. If you cannot afford Microsoft Office, which is very expensive, search on line for Open Office which does practically the same thing and is free!
You can purchase my counterbalanced forklift PowerPoint presentation here.