Some gun control stats
A 2007 survey has the US gun ownership rates at 88.8 per 100 residents. They rank #1 in the world, with Serbia ranking #2 (58.2 guns). Canada has 30.8 guns / 100 residents.
The US also ranks quite high in firearm-related death rates. On average 9 per 100,000 citizens per year, 3 of which are homicides. Canada is about half of that at 4.8 (of which only 0.76 are homicides). FYI, the highest in this category is El Salvador with 50 and a few other central american countries (jamaica, honduras, guatemala) not far behind.
In terms of school shootings, the statistics are quite well documented. The US actually has its own "school shootings" wikipedia page if you're interested: http://en.wikipedia.org/wiki/List_of_school_shootings_in_the_United_States - European, Canadian, etc are referenced here: http://en.wikipedia.org/wiki/School_shooting
5 of the top 10 deadliest school massacres were in the US http://en.wikipedia.org/wiki/List_of_rampage_killers:_School_massacres