FlyerGold II...

Not sure what you did wrong but here are the specific steps that I use everytime:

1. Log in

2. This will take you to the reservation page, select "flights" under advanced search option.

3. That should bring you to the "Reserve a roundtrip ticket" flight search page. Enter a flight, for example YYZ-YVR leaving Jan 1 and back Jan 2. I also set it to business class, display max 20 flight options and choose Air Canada specifically.

4. After you press search, it should bring you to a "Flight selections" page.

5. There's a little bubble beside each flight and you use that to select the flight that you want, let's say in this case, we select AC105 outbound and AC108 on the return, you click on that little bubble beside that flight. Then at the bottom of this page, there's a "Price itinerary" button, you press on that to move on after you've selected your desired flights.

6. That should bring you to the itinerary page which shows you the flights that you've picked and the total price. To the left of where they show you the total airfare, there's a "Select seats" button, you press that to get to the seat map.

I think that's as specific as I can get in writing without showing you in real person how to do it.... but if you are still stuck, let us know and we'll try to explain.