The cheapest by for is the subway. Line 2 from Pudong airport to Peoples square. You will need to change trains at Guang lan road, but this is easy as you just need to cross platforms. This will cost about 8 RMB, the catch is if you are travelling during the rush hour, it can be extremely busy and difficult if you have a lot of luggage. (about 1 and a bit hour)

Taxi is probably the most convient, figure on about 180 to 200 RMB.(30 minutes to an hour depending on traffic)

The maglev is interesting but you will have to then get a subway (line 2 ) from the Maglev terminus at long yang road. The transfer can be a little of a hassle if you have a lot of luggage. Total cost 54 RMB. (about an hour or a bit less)