On a visual approach in an airbus selecting TOGA simply increases the thrust to the max setting. It's then up to you to fly the aircraft in the go around. It's much more difficult than simply selecting TOGA with the auto pilot and mangaged nav engaged where it will fly and navigate it for you.
I've seen pilots get their knickers in a twist during a go around because it hasn't been thought through.
I think the previous replies make it all sound so easy. And it is if the auto pilot is engaged. But for those of us who go places where you can hand fly the aircraft without flight directors etc it requires a bit more thought and flying skills!