Kuala Lumpur International Airport (KLIA) is located 70 km south of KL city.  Direct train service is available via KLIA Express Train.

PUTRA and STAR LRT Line
http://www.putralrt.com.my/index.asp

KTM Trains - Provides interstate travel.
http://www.ktmb.com.my

Taxi are metered and fairly affortable.