The Government of Ontario usually provides COVID-19 updates in live briefings. Most are delivered by Premier Doug Ford (@fordnation) and attnded by other government ministers. Briefings are live-streamed on YouTube, Facebook and by major news networks. Archive is available at: https://www.youtube.com/user/premierofontario/videos
Data is sourced daily from: https://www.ontario.ca/page/2019-novel-coronavirus#section-0 and complemented with reports from https://globalnews.ca/ and https://toronto.ctvnews.ca/.
An Epidemiologic Summary of COVID-19 in Ontario is linked from same data source site. The pdf provides additional information and charts.