The Yogi Entrepreneur: A Guide to Earning a Mindful Living Through Yoga has a number of great tips for getting started with Twitter, but if you really wan to up your game, I recommend you check out these three books. Learn how to quickly grow your following, compose dynamic tweets and use twitter as an extension of the teaching you do in the yoga studio.
Twitter: How To Market & Make Money With Twitter
by Ace McCloud
How to Twitter: Getting Started with 30 Daily Do-ables by Stacey Myers
Twitter For Dummies
by Laura Fitton, Anum Hussain & Brittany Leaning