I am planning a trip to Hangzhou, leaving from South station, and have a couple of questions.

Is it possible to purchase both departure and return tickets here, or do I need to wait until I arrive in Hangzhou to purchase a return ticket for Shanghai?

I know that at the main railway station there is an English speaking booth, but I don't remember seeing any English speaking booth the one time I wandered through South station to check the place out. Can I expect I'll be understood if I say I want a soft seat for a certain date, or would it be best to have a friend write out the details in Chinese and bring that slip of paper along with me?

Thanks for the info.

Yes you can already buy your return ticket.

When i bought my ticket there is one lady from the counter who can speak english. She will ask you if you want a a/c and soft seat train.

also there is a link to info about HZ that was recently discussed within the past month, including some info about getting there and back, train travel, sites to to see, places to stay etc... do a search for the post if you're interested