I recently found a great bilingual map of Tokyo, It's so useful even in Japanese that it's now my main map I carry around when I bike.
"Bilingual Altas of TOKYO", by Tokyo Chizu Publishing (ISBN : 4808509512) is a 1:10,000 scale map (which is a rather detailed map) that covers most of the 23 wards. Major terminal areas are covered in an even larger scaled map. Of course, all city names, area names, stations, streets, and landmarks are written both in English and Japanese. I haven't seen any other bilingual map of this detail, in pocket size and easy carry around.
What's more, an English index included at the end of the altas where city names, facilitiy names, station names can be looked up easily. There's even a section listing points of interest to visit is various areas in Tokyo.
One let-down is that the map is only sold on Amazon Japan. Not sure if you can purchase it from outside Japan.