At the outset let me compliment you on deciding to be a trainer. Atul has already shared a useful document which will enable you to have a preliminary assessment of your aptitude and ability to be a trainer.
You would notice that in the above mentioned questionnaire, the thrust is on communication skills which is critical to become a trainer. The heart and brains of the training still remains the domain knowledge but even the most knowledgeable person would fail miserably as a trainer without effective communications skills. If you are good communicator particularly a good public speaker, half your problem is solved. To further improve your communication skills find a local Toastmasters club in your city and join them.
To get the academic inputs on training you can do the course from Indian Society for Training and Development (ISTD) which is headquartered in Delhi. Alternatively you can also attend some Train The Trainer (TTT) programs offered by private institutions.
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 exercise, examples, 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.
If you have no corporate training experience, ideally take a few sessions for post graduate students in colleges or for social service clubs like Lions and Rotary's so that you gain in experience and also 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 own confidence.
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 84,000 views and 575 followers
www.poweract.blogspot.com - Over 25,000 views and 160 followers
One Train the Trainer Programme is being conducted by Arthur F Carmazzi at Lonavala during December 2011. I am attaching the brochure. One has to invest some time and money but 9 people who had done it with him last year felt it was worth it.
Even i am into HR masters its my last year, in fact last 6 months to go. I am also very much interested in training.
With respect Atul sir can please send me that pdf file in another format, i am not able download it from here.
I would just like share that recently i met a freelance trainer, he said that training has become global recently & trainers have a very bright future. well if that a fact then its a "Thumps Up" to all the present successful trainers & to all the buding trainers.