Are you flying in to LAX? I find that airport very confusing at the baggage terminal for Air Canada. They have this archaic luggage belt that takes forever to bring your bags. Also there are very few signs telling you which belt your bags will arrive on. I usually try to single out one or two people from my flight and watch which carousel they go to. Also, look for a little sign on the baggage carousel that says Air Canada. I think that is how it is set up at LAX.
One other thing to make sure is that all your wrapped gifts are in your checked baggage. If possible, try not to wrap your gifts before going down because they can open them if they like. Also, don't bother locking your bag, they'll just break open the lock to look inside.
In your carry-on luggage, check the items which are prohibited. You are only allowed liquids up to 100mL I believe. That means no water bottles, shampoo, etc.
You can find a list of flight information and travel advisories such as prohibited items on

or on the Air Canada website.
One last thing: check the weight of your bag. If you're going to LA, plan for some shopping down there and needing to bring back lots of loot ( I hear H & M just opened there). Leave extra room in your luggage for purchases and gifts you receive in the States. Also, make sure your luggage is not overweight. They will charge you a certain amount of $$ for each pound it is over. Check the limit on Air Canada's website.
Happy travelling!