What basic information and legal formalities are required to start an e-commerce business?

Here in Ontario, you can just set up as a sole proprietor and start selling online. You do have to pay taxes on your income, so you do have to know basic bookkeeping. If you want to operate under an alias, you have to register that business name with the government, which costs $50 for five years. If you start your own domain, there's no need to register that with the government though as long as you identify yourself as the domain's owner. Once your sales reach a certain level, you are required to register to collect sales tax.