How do you find China supplier?

E-business is more popular than 10 years ago. From the time of China joining in the WTA in 2001, people started searching for products on the internet from China. How do you find a right China supplier? For example, if you wanna buy a large amount of LED tubes, how will you do to get a reliable supplier? Google keyword(LED tube)? or Alibaba.com? or any other tools? I'm really interested in the way buyer looking for vendors.