What is the best way to from Hangzhou to Wuzhen and then from Wuzhen to Suzhou?

From local Central Bus Station, you can find the buses to reach Wuzhen directly. The buses operate from 07:00 to 16:45 and the interval is around 30 minutes to 40 minutes.
From Wuzhen to Suzhou, you can take bus at Wuzhen Bus Station. There are four buses everyday at 08:05, 10:40, 13:55 and 16:40.
Hope the information can help you.