Your teaching of Zumba to children is considered a business to which you are self-employed. The CRA publishes a guide T4002 Business and Professional Income: http://www.cra-arc.gc.ca/E/pub/tg/t4002/t4002-e.html
For turbo tax you would be selecting to report your business income and expenses under "Income > Self-Employment". When in the interview process you will reporting yourself as an Other Business. You can state any name for your business, such as "Jill's Zumba for Kids", there is no trademark requirements and you can use a business name that incorporates your name. Your Industry code should be 812990 "personal physical fitness trainer".
Thy also have a video series: http://www.cra-arc.gc.ca/vdgllry/bsnss/srs-strtngbsnss-eng.html
Additional Information: http://www.cra-arc.gc.ca/tx/bsnss/sm/chcklst-eng.html
Please note, self-employed individuals have a balance due date of April 30th, meaning whatever taxes are owed must be paid by April 30th, however your return is only due to be filed by June 15th of the year.
