Malaysia is a pretty easy place to get about, although nowhere near as touristy as say Thailand, they still have good infrastructure.
BUS – The best and cheapest way to get around Malaysia, buses are frequent and reliable, they also drop you off right in the city centre rather than an airport 30 minutes away. Use BusOnlineTicket.com to reserve your ticket then show up at the station 30 minutes before your bus to collect your boarding pass. You can even take international busses to Singapore.
BOAT – Not my favourite mode of transportation but necessary if your traveling to any of the smaller islands just off the coast of Malaysia. Again they are frequent and cheap, you don’t usually need to book a space.
PLANE – The fastest but also the most expensive (unless you book well in advance) type of transport in Malaysia. If your going off the beaten path then you may end up needing to transfer through Kuala Lumpur first. AirAsia are usually the best within Malaysia.
TAXI – Usually have fixed prices to and from the airport whichever city you’re in, then use a meter everywhere else. Except in Langkawi where everywhere is a fixed price and there is no bus option.