Turning the crank pulley FORWARD ONLY is the safe way to turn the engine. If you turn the cam gear, or if you turn it backwards, you risk the timing belt jumping a tooth.

TDC for #1 is when the cam gear arrow points upwards, while the crank pulley timing mark lines up. When you're adjusting valves, all you're really worried about is that all 4 valves for that cylinder are closed.

#3 is when the arrow points forward, #4 downward, #2 backward.