Dare I say this was one of the best experiences in my life, verymuchso perspective changing in how I view both myself and my world in general. For everyone that travels, I strongly recommend visiting Japan and making Tokyo your first of many visits to their island.
With this in mind, let me say that travel to Tokyo does have some challenges, not so much roadblocks by any means, but some of the things I noticed, when unprepared for them, can make for some complications. This list pretty much encompasses what I feel are the best things to keep in mind when traveling to Tokyo:
1) Learn to speak SOME Japanese: I'm not talking about hitting Rosetta Stone and taking out a small mortgage to get their Conversational Japanese package. At the very least, know how to say "Thank You" (domo, arigato, or domo arigato is more than enough, depending on how polite you wish to be), because that comes up pretty much all the time and it's a courtesy to respond in kind. Possibly most useful is learning the phrase "o-kudasai", where the basic context is "if you could please", but really it's an all encompassing phrase that can be hacked for assistance, instructions, even when ordering food. Since Japanese works similarly to German, many Western words and phrases can be ported over to Japanese (e.g. Hamburger, taxi, camera, etc.), so by simply inserting what is needed before the phrase "o-kudasai", and with a polite gesture, most Japanese will understand the context of what is needed (e.g. pointing to the A-Set meal on a menu and saying "A-Set o-kudasai").
2) Know how to get out of the airport: It's best to understand what options are available and where they reach, not just to make transit easier, but because transit in Tokyo can become expensive quite quickly. For example, as Narita is approximately 50 miles from Tokyo, the only thing more expensive than taking a taxi into the city is taking a helicopter, and not by much! Likewise, there is a Rail line (called the JR Airport Line) that runs from the Narita terminus with transfers from it's line at Chiba station to several local lines, which is probably the most inexpensive option, but, depending on the stop, can take well over 2 hours. From Narita airport, the most direct options are to use the Narita Express rail (N'Ex) with stops at Tokyo and Shinjuku station, or to charter a limo bus with direct stops at most major hotels in all of Tokyo's districts.
3) Know the Tokyo Metro/J.R. Lines: The Tokyo Metro and J.R. lines are pretty much unavoidable when wanting to tour around Tokyo, with the exception of staying holed up the residing district surrounding the hotel (FYI, that option is actually quite doable in districts like Akihabara or Shinjuku as it seems like there's a million things to do in both of those areas). The most recognizable and easiest to use line with stops at the six major Tokyo stations and several popular districts in Tokyo is the J.R. Yamanote, A.K.A. the Green Line, A.K.A. the Big Green Ring. This map http://upload.wikimedia.org/wikipedia/commons/5/5e/Yamanote.png
is probably the clearest english explanation of the Green Line and all of it's stops. It's incredibly quick and ridiculously punctual, neither late nor early quite consistently. I'd strongly recommend printing this map for 2 reasons:
a) it's significantly easier to understand than the Japanese maps you'll find.
b) it's invaluable in calculating out your rail fares.
The 2nd point is much more important since, though purchasing tickets from a kiosk can be done in English, trying to figure out fares isn't. At every station serving the J.R. Yamanote there is a similar map showing one way fares between endpoints. For example, between Shinjuku station and Harajuku station is a number that says 130, meaning a one way ticket between both stations is 130 yen. This is easy enough except that the station names on the fare map is in Japanese! Having an english map made things a million times easier only because I was able to line up my endpoints from my english map against the stations on the japanese map and figure out my fare without the hassle of having a rail officer direct me to where the fare readjustment kisok was!
Every line in Japan, be it the aboveground J.R. lines or the underground Metro lines work exactly the same, and just about every spot to visit in Japan has instructions on how to use the rails to access their location, complete with the station names and connections. I became quite reliant on Wikipedia after a while as it is probably one of the best resources for the Tokyo rails, and would recommend it to all travelers wanting to tour around the city.
4) Be Polite: Though it should be a given when traveling to a different country to maintain a modicum of etiquette, I feel this is moreso important when visiting Japan. Their degree of manners is quite impeccable, even during the busiest parts of the day, as I had discovered one day during rushour on a car packed to the gills with commuters with nary a one of them being rude or obtrusive, with nothing more than a muted hush of students quietly chatting in one corner, while everyone else made it a point to be as respectful of everyones space as best as possible. Being polite in Japan I learned goes a long way in earning respect with the locals, especially when traveling as a tourist, and most all Japanese recognizes it immediately and is more apt to to out of their way to help when assistance is needed.
5) Bring a change purse: Japanese currency is a trip considering they simplify their currency to it's base unit, the Yen (¥), which would be the American equivalent of basing U.S. currency around a Penny. There is no such equivalent as a Dollar equalling 100 pennies or a Pound equalling 100p, there is simply a ¥100 coin equalling...well...100 ¥1 coins. Coin denominations go ¥1, ¥5, ¥10, ¥50, ¥100, and ¥500, after that it goes to ¥1000, ¥5000, and ¥10000 yen bills. Most major stores will round everything up to the nearest ¥10, but it is surprising as to how much coinage is generated after breaking a few ¥1000 bills.
6) No Smoking: for a city that embracis smoking, I was surprised to learn that several parts of Tokyo have become No Smoking, INCLUDING outside on busy public streets unless you are in a designated smoking area. The idea seemed absurd to me at the time considering it's the outdoors and all, but after realizing how many people are crammed in Tokyo it seemed more than reasonable that a city of that magnitude would want to go that route, and for the most part, this law is accepted and enforced in Tokyo. From first hand experience, when having a cigarette in an area I thought I could get away with it, a patrol officer noticed and POLITELY directed me to a smoking area, gesturing to me that I should finish my cigarette there instead of on the streets. On a sidebar, cigarette machines in Tokyo are set up so that no one underage can buy a pack of smokes. All tobacco machines are locked down for age verification under a smart card system managed and issued by TASPO to any legal aged applicants. Interested smokers need to apply for the card in advance with proper submitted documentation to receiving one, and no tobacco machine in Tokyo can be accessed unless a smoker posesses a TASPO card.
7) Google Maps kinda sucks: This is not to say that Google Maps is useless when visiting Tokyo, just that it has it's shortcomings. For starts, it's helpful when searching for something in Tokyo to know the proper Japanese name of the place you are searching for IN JAPANESE, right down to using Kanji characters. Most hotels in Tokyo you can get away with searching using roman text (e.g. The Sunroute Plaza in Shinjuku), but trying to search for a specific restaurant in tokyo can be a challenge unless you can find a romaji (roman texted japanese) link that points to it's Japanese name.
After finding it's japanese name however, a Japanese address is usually associated and is easy to cut and paste to generate point to point driving directions in Google Maps, which is especially useful when handing to a cabbie when taking a taxi in the city. Walking instructions, however, is an entirely different story.
Not only does Google Maps for Tokyo not have street names, but walking instructions usually comprise nothing more than just "Turn left - 50 meters". This link is a perfect example of such madness when trying to get from the Hotel Sunroute Plaza in Shinjuku to the Golden Gai district:http://maps.google.com/maps?f=d&source=s_d&saddr=Sunroute+Plaza+Shinjuku+Hotel,+Shibuya+Ward,+Tokyo,+Japan&daddr=Japan+(La+Jetee)&hl=en&geocode=FXuKIAIdgaJTCCFt8cooRrszMA%3BFdWlIAIdebhTCCGmC0NstC8qvg&mra=ltm&dirflg=w&sll=35.69052,139.701676&sspn=0.012199,0.018861&ie=UTF8&z=16
However, one of the upsides to using Google Maps is what it lacks in street names it more than makes up for in photos and street views in Tokyo. Between both, I was able to find most of what I was looking for in Tokyo, however, there were points where either the pictures were outdated or the coordinates were completely incorrect and I ended up getting lost.
In the end, I'd say Japan was amazing simply because it redefined the way that I traveled. I never realized how when I'd travel often I would just jump into an area without really understanding the area. Having to travel in and around Tokyo forced me to have to research out the area, to learn more than I would have if I was to travel domestic, and in that, not only did I understand how to travel in the area, but I gained a much deeper appreciation and understanding of the area as a whole.