There should be enough on GL's site to get you started. However, generally speaking, if you are using a TAM or a Leo, you want 22mm oil pipe work and 15mm vapour pipe work. If you can fit 28mm pipe work between the tank and the pump suction, so much the better.
As for dimensions, it's what fits the space you have available. There are lots of photos of examples on GL's site. Just a few basics that are some times overlooked:
1) Make sure all the pipe work and processor are sufficiently high off the ground to get your glycerol collection container under the drain. I'd use that as your starting point and layout the pipe work and tank from there.
2) Make the condenser as long as possible, but try and have the top of it not much higher than the top of the processor.
3) Keep all the pipe work as short as possible, using as few bends as possible and try to use formed bends, especially on the pump suction.
4) Don't spend too much time making it look fancy and neat, because a pound to a pinch of poo, you'll be modifying it within a few months!
HTH
