Entry to Canada (crime, vacation, money)

[Stripes17]

Can anyone provide a good resource that explains restrictions on entering the country of Canada from the US for a short term visit (on business or vacation)? I've heard stories from co-workers that some of our employees have bene stopped at the border and refused entry to Canada as they have had some minor indiscretions in their past. Sometimes they've had to pay money and get a waiver(?) and other times they've been turned back at the airport. I'm curious to see what would qualify as a red flag to stop entry.

[darstar]

For the average US citizen , the most often reason to be denied entry in to Canada , is a past DWI. Canadian Customs has a direct link to the FBI files , at almost every Port of entry. You don't have to be convicted of any crime , just the fact that the case was entered in the data. Any domestic problems , that have the word " harm , violence , gun , etc" , will deny you entry. Many Custom agents , will , if they think you are a good person , issue you a visa , for a specific amount of time. They take Visa and Mastercard , the "fee" is about 500.00. That will vary as to the serious nature of your reported case.
Usually , this visa , is one time only , which means , you will be denied and future entry , for at lest 5 years. You can appeal to the Canadian Consulate near you , but it is seldom overturned.

[allforcats]

Here is everything you need to know, from the source:
http://cbsa-asfc.gc.ca/publications/pub/rc4161-eng.html (broken link)