Canada
For an introduction to the patent application process in Canada, start with CIPO's tutorial and the application section of the Guide to patents.
Tutorial: Your Patent Application | Guide to Patents
United States
USPTO has produced separate online guides for the three types of U.S. patents.
Utility patents | Design patents | Plant patents
International
The Patent Cooperation Treaty (PCT) allows you to apply for a patent in multiple countries through your own government's patent office.
Patent Cooperation Treaty Kit
Protecting Your Investment Abroad: Frequently Asked Questions about the Patent Cooperation Treaty (WIPO)
PCT Applicant's Guide
