Travel by bullet day time from Shanghai to Beijing

Even I am Indian and resident of Singapore my wish is to travel in bullet from SH to BJ and return. Planning to visit Mar/ April 2016. Please advise how soon I plan to buy tickets. I surprised with many bullet frequency between. How to book it on line and where to collect it for travel. Whether can we get vegetarian food in bullet ride? Announcement in train is in Chines or English. Please reply.

Regards
Hari Suthar