Well, I just got back from 4 days in Tokyo, and for not speaking the language well, I managed to survive and get around well enough.
I can confirm the usual tips:
Try not to go in the summer, unless you REALLY like the heat and humidity.
In the city, the subway is your best friend. Pasmo card was a life saver.
If you get a craving for mass produced American food, McD's are everywhere and KFC can be found too (including Akihabara).
Watch out in crosswalks. Drivers are VERY impatient.
If you want a quiet part of town to stay, Koujimachi is a great place to consider.
If you need to pull money from a bank outside Japan, you'll be spending some time trying to find an ATM that will do it. One option is the Japan Post Office Bank. There is also an HSBC bank in Marunouchi.
Try not to go to Roppongi alone, especially if you get off the main road. That's where you'll find the guys trying to get you in their bars to drug and rob you. I gave them a flat out "NO".
Enjoy Akihabara and expect to be broke by the time you leave. Too much cool stuff.
That's about it for now.
Enjoy the trip!