If you're looking for interesting things to do,
Time Out Tokyo usually has daily event information, and a lot of sight seeing recommendations.
If you have enough money you could buy a
Japan Rail Pass, which allows you ride most train systems without a ticket (except the metro lines, some different types of trains, and some shinkansen lines). But if you're not likely to use the shinkansen it's really not worth it, just be aware that you're going to have to set aside money for travel.
The second time I went to Tokyo I was going to like six places a day, and ended up spending over $200 in travel expenses really quickly. So, maybe figure out where you can spend days or half days and not spend like two hours in one place before moving onto another like I did(;´▽`A`` lol
Also, you have to consider the
different types of trains, but Tokyo has a lot of the announcements in English and it also has train line maps in English next to the Japanese ones in most places so you should be okay with that.