You can take bus from Sukumvit area or from BTS skytrain, any stations along Sukumvit rd.
The air-conditioned bus number ; 25, 508, 511 (take these bus to the end route)
If you want to go to attractions such as Crocodile farm, The ancient city or Bang Pu, you have to transfer to local bus no.36 (call Song Thaw), or take Tuk Tuk...
Samut Prakarn Bus Terminal - Morchit Bus Terminal
Bus # 145 - Airconditioned Bus
Bus Fare : THB 16