[Sangetsu]

The map and schedule on JR's Hyperdia are always accurate. I access it on my telephone (like everyone else here) when I need to find out when, where, and how I want to get somewhere.

Generally speaking, as long as you have 1 or 2 minutes to transfer trains, you should have no trouble. In most cases the platforms are very close to each other. Even if you do miss your connection, the trains run every few minutes, so catching the next one is no big deal.

The signs are in Japanese and English, and are very large. They are generally color-coded as well, for example, the Chuo line uses orange signs, and the train has a large orange stripe down the side. The Keio line is red, the Yamanote line is green, etc. On occasion, different train lines use the same platform, so knowing which "color" your train is can be a big help.

The Shinkansen trains do not run so often (unless you are at a major station like Tokyo or Shin-Osaka). But 5 minutes is more than enough time to transfer trains (so long as you have your tickets in advance).