Well, you've probably heard this a billion times.
First of all, Japanese people are generally bad at english conversation. It's not their fault since most of the TV-shows and movies making its way to the land of the rising sun are dubbed. Fear not, however, there is hope.
First of all, I'd get a good point-and-speak book. The one I'd REALLY recommend, which saved my ass countless of times, is the JAPAN - English Edition. The name is a bit hard to look up, so try to find the author Toshiya Enomoto. There's a VERY large mall at the Shinjuku station in Tokyo, I don't remember the name for it though, and there's a very large book-store in it. They stock english-languaged books and you're bound to find JAPAN - English edition there. This book was actually recommended to me by a Brit I met purely coincidentally while riding the subway to Shinjuku.
Secondly, although it seems you found yourself a hostel, I'd recommend looking into New Koyo Inn. This place has most likely been brought up already, but if not... it is THE place to live in when you're staying in Tokyo. The fee is insane, it's somewhere around 20 bucks a night for a, albeit small, bedroom with a traditional japanese fuku and tatame-mats. The floor was just big enough to hold three of me, and the walls are thin as paper, but overall it's a comfortable place.
Also, they have hours where you're free to use the bath... do it, it's a great experience (but don't miss out the larger public bath-houses though, they're awesome). Just don't do my mistake and think you can't pour cold water into the tub. For five days I pained myself through hours of boiling-hot bathing until one of the regulars asked me if it was too hot. Sufficient to say, it's a lot nicer to sit in water that doesn't scald you.
Thirdly, plan your trip. Seriously. I was in Tokyo for nine days and I mostly went around town visiting parks, gardens and the fish-market... that is all fine and dandy if you like that, but consider Akihabara. A trip there could either take several days or a few hours, depending on your interests and ability to comprehend japanese. If you have the time and money, I'd really recommend a visit to Kyoto, it's awesome, but sadly the farther you get from Tokyo, the worse the english becomes.
Oh, and one thing... try not to ask people for directions unless you REALLY need it. It's customary to help people who request it, and you can, even if you don't intend so, really put the stress on someone if they don't know where you're going. I had people calling up friends on their cell-phone, desperate to show that they knew directions.
Tokyo is NOT an easy city to find your way in, but it is tons better now than a couple of years back. The subways all have signs both in Japanese and English and one can easily figure out where to change trains and so forth...
Anyway, hope your trip will be fun and exciting, I know mine was. :)