I did this route back in 2002 while on business. Since I had 2 local colleagues accompanied me, I didn't pay much attention to finding my own way around.
This was in late April. On the train, Christmas music was blaring the entire way. Go figure. There was food and drink (include hot tea poured from a tin tea pot) on the train. But most travelers (in 1st class) brought their own tea and food. Upon arrival at Nanjing train station, the scene outside the station was extremely confusing. We had to literally shoulder our way to find a taxi. Lots of people, bikes, buses, cars and trucks around. The traffic didn't seem to have any order or pattern. If I was there by myself, I would be a bit perplexed.

That said, here are couple of tips: Have someone write down the station (in Chinese) that he has to alight. Plus the address in Chinese where he has to go. Show that to the taxi driver. Taxi drivers in China are fine, even though they tend to drive too fast. But they won't cheat you.