After arrive at the airport, you could take metro Line 2 to People's Square. However, it is not suggested if you have some luggages since you have to make transfer enroute. For instead, you could take shuttle bus Line 2 to its terminal at Jing'an Temple, and then take a taxi or the metro Line 2(just two stops) to People's Square where the Charm Hotel is not far.

For leaving from Shanghai Airport, you'd better go to Jiang'an Temple bus terminal to take the shuttle bus around 06:30.