Terrifying train map
I'll walk you through how to use the trains, so if you ever come to Japan, you won't freak out and get on the wrong train.
When you first walk into a station they will have these machines along one wall. This is where you buy your ticket. All the ones I have seen have English buttons, so if you can't speak Japanese, don't worry! You can still buy a ticket. My suggestion is not to worry about which one to buy, just get the cheapest ticket, and worry about adjusting your fare later if it is not enough. For those of you with a train card, you can also add money to the card here.
Next is the ticket gate. The arrows will tell you if you can enter or not. If people are coming through from the other way it will have a red do not enter symbol. If you have a ticket there is a little slot to put it in. If you do not have enough money to go through the gates will close and you have to go to the fare adjustment machine. If you have excess money it will give you your ticket back. If you have the right amount it will just keep it and let you pass. If you are using a card, just put it on the little blue circle on top and it will read it.
Once you get through the ticket gate you will see signs like this. They usually have Japanese, English, Chinese and Korean. They tell you major stations that the trains are stopping at, so you just have to know what is in the general direction that you are going and pick a side. If you absolutely have no idea each station has an information kiosk. Just go in and in whatever language you speak try to explain where you want to go. The workers will usually just give you a paper map, draw lines and circles around which stations you want to go to and transfer at. This is a magical place and why I have not so far gotten lost. If I ever don't know which train I want I just go ask my friends at the kiosk and they tell me exactly where I need to go.
Once you make it to the platform there will be these billboards. They flash from Japanese to English telling you what type of trains are coming (express, local etc), how many cars they have, where they are going and what time they are departing. I usually take the same trains every day, so I barely look at this, but if you are a newbie it is so helpful.
If you get on a train and are still nervous you got on the wrong one, all trains have something similar to these screens. They tell you where you are and which stations are coming up. If they are not stopping at a particular station, that station will be in gray instead of black writing. They flash between English and Japanese, so I think it's fun to try to test myself and see if I can read which stations we are going to when the writing is in Japanese.
Last is this miracle machine. This is the fare adjustment machine. If you are trying to leave the station of your destination, and the gates close on you, don't panic! Don't freak out and push yourself and your suitcases through the gates and then hope station workers didn't see you just stealing a ride. That is not necessary. Just calmly look around for this machine. Once you find it you either put your ticket or card in, and it will tell you how much more money you need to pay to equal the amount of your ride. Once you give them the money, they will give you a new ticket and you can go through the gates like a normal person.
Well, there you have it! How to use a Japanese train/station. I hope that you will find this helpful, and if I missed anything just comment with your question and I will do my best to answer it!
P.S. The tea of the day is peach tea ^_^