I will be traveling from Chicago to Toronto on United and then on to Halifax via Canada Air. My questions is do I have to go to baggage claim in Toronto to pick up bags and then recheck my bags? I only have 1 hour and 7 minutes between flights. So a little concerned that I can't accomplish everything (baggage, customs, etc.) in that time frame.
The definitive answer is waiting for you at http://www.torontopearson.com/Connecting.aspx
Assuming you meant Air Canada (a United partner) Yes, you will need your baggage while you clear Canadian customs, and then you will recheck it.
Having connected from the US to Canada via Toronto many times, I would be nervous about that connection if I were you.
The walks will be long. This is particularly true if your plane is arriving in Toronto from a smaller U.S. airport, which flights use small commuter jets and turboprops. These planes arrive at Gates F84-99, which is a small section of the airport (essentially a long hallway, with minimal services) that is well-separated from the rest of Terminal 1. There is a sign at the beginning of this section that says something like "7 minute walk from this point to Gate F99; no shops beyond this point." Flights from larger airports (including Chicago) usually use larger planes, which generally use the gates closer to the main part of the terminal.
The amount of time you'll need to wait in line for Customs is highly variable. The last time I was there I sailed right through, but you can also stand in line for a good 20 minutes if you arrive right after a couple of big jumbo jets.
After you talk to the Canada Customs officer, you'll need to wait to retrieve your bags. Once you've got them, you can do your final clearance through Customs, which usually just consists of you handing your customs card to the agent at the exit. You have to have all your checked bags with you to do this; them's the rules. I haven't been through Toronto with checked bags recently enough to comment on how long this can take (though if you're delayed getting through the line, you can at least expect not to wait as long for your checked bag.)Luggage procedures at YYZ have changed. See edit below. At this point, you need to put your bags back into the system. This is probably the easiest part; follow the signs for "Connecting flights to Canada" and they'll lead you to a conveyor belt you can drop your checked bag on. You won't have to talk to an agent or anything.
You'll then need to go through security again; I believe that once you've exited Customs, you've exited the secured area, and that there's no way around this. This can also take a while, depending on the time of day.
To get this all done in 1:07 is certainly possible, but you don't have much margin for error. You might consider calling up whoever sold you the ticket and seeing if they'll switch your Chicago-Toronto flight earlier or your Toronto-Halifax flight later without any fee; I had a good experience doing this with Air Canada earlier this year. (In my case, one of my flight times was shifted by Air Canada, leaving me with an eight-hour layover, but they booked me on a later incoming flight free of charge.)
Edit, Jan '16: Having flown from Hartford to Winnipeg via Toronto (and back) in December 2015, I can now say that they have upgraded their baggage system, and that you no longer need to re-claim your checked bags when flying either into or out of Canada via YYZ. This definitely saves you some time. Of course, there's still the possibility, as with any tight connection, that you could make it onto the connecting plane but that your checked bags don't.