Originally Posted by NewbieRunner

From the bus arrival gate go up the escalator and when you get to the top follow the signs for Z gates. This will take you to the right of passport control booths and a corridor to the bottom of the escalator taking you up to the Skyline train platform. The train leaves every 2-3 minutes and takes less than 2 minutes to T1 Z. There is security check somewhere on the way.

Frankfurt Airport is actually very well sign-posted. I will post some photos later. If you can read the alphabets and numbers, there's no need to talk to anybody to find your way around.