Trip to Italy

If you have 6 days for this trip. You can go to these three cities together because you have got enough time. I will suggest a schedule as below:

Day 1: Rome
Day 2: Rome
Day 3: Rome -- Venice (5 hours trains)
Day 4: Venice
Day 5: Venice -- Milan (3 hours trains)
Day 6: Milan
You can simply get the train ticket in the ticket office of the train station. Actually if you are interested in visiting one more place. You can go to Florence in Day 3 as well. From Rome to Florence, it takes 2 hours only on train
You can book the accomodation of Italy through the travel agents in Hong Kong, but usually it's for hotel. If you are looking for hostels, B&B or youth hostel, you need to book it by yourself.
The accomodation is Italy is quite safe, but those important things and valuables, please bring it along, or keep it in the safe in room or safe boxes in counter.
Choices of hotel depends on your budget. A simple cheap hostel will cost you around 60 - 70 euro in Italy. It's very hard to suggest a single choice for your consideration because the service standard can be improved or worsen within a short time. I will suggest you to buy a travel guide in bookstore. There is plenty of information. Also, you can go to www.hotelclub.com to have a look. Don't only focus on the price, but also you should read those comment from other travellers. You will find out your choice within a short time.

Ciao .