Think about taking a small Roley bag or trolley on your shopping excursions. All that fabric and books can get heavy!
The train system can seem daunting at first. But once you work out which line you need to get on, it's quite easy! All the ticket machines are bilingual and onboard announcements are also made in English. I found this site such a time saver, just put in your destination and it will give you the line and fare. Another option with the fare is to buy the lowest fare of Y130 and just top up your ticket at your destination using the adjustments machines before exiting.
If you get to a Yuzawaya store ask about their discount card. You will get a 10% discount across the store. It's free to join and the staff didn't seem to mind that we were using an international address on our application form.
Fabric in Japan is sold by the metre. Which is approximately 4 inches longer than a yard.
Looking for a hotel in tokyo? I would highly recommend the Kadoya hotel in Shinjuku. It's reasonably priced, central, clean and quiet. It also has free internet access in your room or you can use the PC in the reception area if haven't brought your own laptop. The post office is also directly across the road, perfect for grabbing some cash or sending home all that excess baggage!