To become a plumber in Ontario, you generally need to follow these steps:

1. Education: Obtain a high school diploma or equivalent.

2. Apprenticeship: Complete an apprenticeship program. In Ontario, this usually involves a combination of on-the-job training and in-class education. The duration of the apprenticeship can vary, but it's typically around 4-5 years.

3. Trade School: Enroll in a plumbing trade school to complete the in-class education requirements of your apprenticeship.

4. Licensing: After completing your apprenticeship, you'll need to pass the Certificate of Qualification exam for plumbers. This is administered by the Ontario College of Trades.

5. Experience: Gain practical experience as a plumber. This is often a requirement to become a licensed journeyman plumber.

6. License Application: Apply for a plumbing license through the Ontario College of Trades or the successor organization that handles skilled trades in the province.

7. Continuing Education: Keep up with any required continuing education to maintain your plumbing license.

Remember that the process and requirements might change over time, so it's a good idea to check with the relevant regulatory bodies in Ontario for the most up-to-date information.

The salary of a plumber can vary based on factors such as location, experience, specialization, and the demand for skilled workers. In Ontario, as of my last update in September 2021, the average annual salary for a plumber was around $60,000 to $70,000 CAD. However, these numbers can fluctuate over time and may vary from region to region.

Plumbers with more experience, specialized skills, or who have established their own plumbing businesses can potentially earn higher salaries. It's a good idea to research current salary data for plumbers in Ontario to get a more accurate and up-to-date understanding of the earning potential in the field.