Looks like I have an opportunity to spend a long weekend in Tokyo soon! I have to fly to Guam and Saipan for work again. One of my flight options has a layover in Tokyo so I figured, why not pause for 3 days and take a look around. It isn't a lot of time to see the city, so I would really appreciate any travel tips from Cyburbians who have been there recently!

Where should I stay?
Can I just stick to mass transit and not get lost without knowing Japanese?
What places are "must sees"?
Where is the best Karaoke Bar?