One of the best and convenient way of visiting the Tanjong Pagar area is to take the efficient MRT sub-way system and alight at the Tanjong Pagar MRT station in-between the Raffles Place MRT station and Outram MRT station.
If you are taking buses to the Tanjong Pagar area, then you can take SBS bus number 80 or 145. Bus number 80 travels along the city area to South Bridge Raod before reaching the Tanjong Pagar area, then goes along Keppel Road to the Harbourfront ferry area (and the new shopping centre called Vivio City).
More information is at the SBS bus website below.
If you are driving to Tanjong Pagar area, parking can be expensive especially during weekdays and Saturdays. There is a carpark at Craig Place (along Craig Road) which has car park which charges fees per minute (I think it is about 3 cents per minute). This is relatively cheap and you pay for the exact time which you park your car in the carpark.