http://www.expatax.com The Canadian Relocation and Expatriate Taxation Resource Centre offers prosaic warnings ("tax planning for expatriates is complicated") and bad jokes ("moving outside Canada does not have to be a taxing experience"), as well as an essential income-tax organizer. It also includes guidelines on foreign property ownership and articles on offshore banking.
http://voyage.dfait-maeci.gc.ca You'd never guess from the URL, but this is the Department of Foreign Affairs' help site for Canadians who want to live abroad. Useful information about tax and RRSP rules, especially for retirees eyeing a condo in Florida.
http://www.grasmick.com/equalize.htm From the Buffalo, N.Y., law office of Joseph C. Grasmick, a business-immigration attorney: FAQs that address "How Canadians can save taxes on short-term assignments in the U.S." and "Are relocation expenses taxable?" The answer: mostly, no.
http://www.taxprophet.com A U.S.-based site, useful for its foreign taxpayer advice, with articles on investing in the U.S. thrown into the mix. Real-estate information deals specifically with California, but there are some general tips.
http://www.ccra-adrc.gc.ca The Canada Customs and Revenue Agency, formerly Revenue Canada, has on-line tax guides, pamphlets and schedules for non-resident Canadians. Look in the "forms and publications" section for a guide to moving to the U.S.