On my 1.9 AAZ, this is what I do:
Jack up the left hand front wheel so it turns. Take the top cambelt cover off. You will see four large holes in the IP sprocket and an extra small one between two of the bigger ones. This is the IP locking hole. Put the car in 5th gear and turn the jacked up wheel until the extra small hole is in about the 4 o'clock position (this is close to TDC cylinder 1). Now, find the little plastic cover with a tab attached on the top of the gearbox next to the engine, and remove it - it comes off really easily. Look in there and you will see the edge of the flywheel with its teeth. Turn the jacked up wheel slowly back and forth whilst looking at the flywheel edge, you should be able to find the timing mark and line it up with the little pointer. The mark you are looking for on the flywheel is a 0.
If you are doing this in the dark with a flashlight or headtorch, make sure that the light is not shining directly down on it (ie coming from the same direction you are looking) cos you won't see the mark. I usually prop a flashlight somewhere in the engine so that it shines on it at an angle.