Hi There,
I want to tell something if you don't mind. The workshops on topics like Communication,motivation, Positive Thinking etc., are something that you cannot conduct just by reading books or articles. You need to observe lot of things before you actually could implement them and also you need experience.
As you said, you are inexperienced in this field, I would suggest you to contact some professional trainer for the workshop.
If you agree to what I have said, I can help you in conducting those sessions for yur people. I am in this field for last 10 years.
ALL THE BEST.