You mean you have two days and two night in Suzhou, for you are leaving for Hangzhou in the early morning of the third day?! I think time is not enought. The hotel is in Guanqian Street, a well known pedestrain street in the city, so you can have your night time wandering there. Take taxi, the Humble Administration Garden can reached in a couple minutes. You need to spend over hald a day there at least. Take taxi to Suzhou North Bus Station. There are buses to Zhouzhuang. The last bus back to Suzhou leaves Zhouzhuang at 5pm. Suzhou West and North Bus Station both have buses to Wuxi, about one hour's driver.