Transport Tube
The main block of this mod. They're a pneumatic tube that will transport anything that enters it through itself, this includes players, monsters and animals (as long as they fit inside!) Pretty simple really, something goes in one side and comes out the other (usually faster than they went in.)
Note that when you place these blocks they will automatically orientate themselves based on the side of the block you placed them on. If you place them on the top of a block they will push everything upwards, for example. To stop this behaviour, put the transport tube in a crafting grid (either on it's own, in a group of four or a group of nine) and the direction will be locked to what it says on its tooltip. To change it to a different direction, or remove the lock entirely, put it back into the crafting grid - it will cycle through all the available directions and no lock.
Tube Station
A block designed to make it easier to get in and out of Transport Tubes. Simply attach these to the end of a Transport Tube and walk inside, you'll be taken away instantly. If you get deposited into a Tube Station from a Transport Tube, you'll stay there and won't bob up and down as if you didn't have one. If you want to go into the station but not get carried away instantly, simply sneak, and you'll stay there for as long as you're sneaking.
Tube stations can be placed in series with each other. You will always zoom past stations and go to the end of the line, but if you wanted to get off on an earlier stop, hold sneak just before you arrive at the station - you'll stop and as long as you hold down sneak you'll be able to get out - but if you stop sneaking without getting out you'll be carried away.
Note that you do not need a Tube Station at the end or beginning of any Transport Tube systems - they're just to make it easier. There are instances where you may not need an entrance or exit tube station. For example, transporting chickens to a different area.