Your goal to avoid a lawsuit is certainly a worthy one.
Writing a book in your own words and based on your own personal experiences should generally not be a problem. It is only where you introduce or rely on the teachings of the master craftsman that you could you run into difficulty - although, based on the minimum amount of information you have provided here, it is impossible to say what these risks, if any, could be.
Nothing can guarantee 100% that you won't be sued over what you write, as anyone can sue for pretty much any reason at all, whether a suit has merit or not. Your best bet in meeting your goal of not being sued is to have your book plans and your final manuscript reviewed by an attorney. He/she can help you reduce your risks by pointing out any problem areas which you can then eliminate through editing. Insuring your book against the possibility of any lawsuit is also wise.
Good luck.