Here is a short list of suggestions from the Winnipeg Police “Protect Yourself Against Charity Frauds”

Protect Yourself Against Charity Frauds
To protect yourself from fraud, follow these tips before you donate.

Learn and confirm
?Before donating, confirm that the charity is registered with the Canada Revenue Agency (CRA). Consult the CRA Charities Listings or call 1-800-267-2384.
?Confirm that you will receive an official donation receipt if you want to claim a tax credit.
?Ask the charity what activities your donations will support.
?Make sure you know who you are donating to. Sometimes fraudulent charities use names that are similar to well-known and respected charities.
?Call the charity’s head office or visit their website to learn more about its finances and fundraising activities. Ask for its annual report.
?Beware of schemes that promise you tax savings greater than your cost, thus allowing you to “profit” from donating to a registered charity. For complete details, see the donor alert section.
?Ask yourself: Am I satisfied that my donation will support the work of a legitimate charity?
?At the beginning of each year, decide which charities you can afford to donate to. Send your checks directly to their head office, and feel good about giving. When approached for contributions, you can say that you have already given and leave it at that. Perhaps you will consider their appeal next year when you decide on the charities you can afford to give to.

http://www.winnipeg.ca/police/TakeAction/charities.stm