If you have the rear heater, I think it's something like 9.3 qts. You will want to fill the cooling system via the radiator, if it is low, making sure to purge the air out of the system as recommended in the service manual. After that, you should fill up the reservoir bottle with a coolant mixture to the MAX line. Any time you add coolant after that, add to the reservoir bottle.
ETA: Yes, 50:50.