At the outset, let me compliment you on deciding to be a trainer. I am taking the liberty of adding my suggestions for your consideration.
Communication Skills
To be a good trainer, a prerequisite is good communication skills, particularly effective presentation and public speaking skills. However, the heart and brains of the training still remain the domain knowledge, but even the most knowledgeable person would fail miserably as a trainer without effective communication skills. To further improve your communication skills, find a local Toastmasters club in your city and join them.
Academic Inputs
To get the academic inputs on training, you can do the course from the Indian Society for Training and Development (ISTD) as planned. Alternatively, you can also attend some Train The Trainer (TTT) programs offered by private institutions.
Getting Started
To get going, focus on those topics that you are familiar with, confident about, passionate about, or have a good grounding in. Keep updating yourself by reading extensively and start outlining the broad course contents keeping in mind the type of audience you are likely to address. In particular, pay attention to the type of exercises, examples, and activities that you will use during the program to reinforce a point or make the learning relevant. I would also suggest that you attend some corporate training by professionals on topics of your interest to get a feel of how it is structured and delivered.
Gaining Experience
If you have no corporate training experience, ideally take a few sessions for postgraduate students in colleges or for social service clubs like Lions and Rotary so that you gain experience and can fine-tune your material. Once you are confident, approach a few corporates, and the first few training programs are vital for future reference and for your confidence.
Inspirational and Motivational Blogs
I would also invite you to visit the following Inspirational and Motivational Blogs which can also assist you in improving your vocabulary and communication skills:
-
www.actspot.wordpress.com - Over 1,10,000 views and 700 followers
-
www.poweract.blogspot.com - Over 33,500 views and 180 followers
Best Wishes