Filing taxes in Canada is relatively simple compared to the USA. See the site for various options, but try to find ones not operated by American firms such as H&R Block and TurboTax.
From a cursory search, TaxTron, GenuTax, Better Tax appear Canadian. Many are Pay-What-You-Want model.
If you have a complex tax situation and/or can’t file online, and/or don’t want to do the paper return yourself, consider seeing an independent Canadian accountant.
In Quebec I use Impôt Expert which was developed by the same company as TaxTron. There’s an english version of the tool called Ufile.ca