I grew up in the United States, so normally handshakes are the normal thing to do when meeting somebody, but it depends on the person. There are some people who, due to religious beliefs, are not allowed to touch members of the opposite sex, so if you offer them your hand, they will politely refuse to shake it. 

Sometimes in the U.S., however, we are very informal. For example, it's not considered rude if you're at a party and meet a lot of people at the same time, and just kind of wave and say "hi," instead of going around and shaking everyone's hand. In a business meeting or more formal setting, it is generally more acceptable to firmly shake the hand of each person you meet. 

One old-fashioned rule of social etiquette is that a gentleman does not offer his hand to a lady for the purpose of shaking hands.
If he is being introduced to the lady, he must wait until she offers her hand to be shaken.

This old convention does not apply in business situations nowadays.

Shaking hands in Canada Is never considered to be rude.
In fact, it is a friendly gesture.

Guys I really thank you all! Your comments were pretty much relevant to me. I really aprecciated that. 

There`s just one thing: Julie, you got my attention when you said Americans are informal sometimes. In my country many people believe Americanas are a bit formal most of the times. What`s the real picture? Please tell me Brazilians are wrong!