Replying to [Global_Trader]:
We have seen many replies here, and it is very true that the agent should know the product, in some cases you can give your requirements of the tests you want at the production.
China is a large country and to have one agent in that area where your supplier are can be better, but not always the fact that agent = quality checking, some agents would use another person or company to check the products, dealing with your order and communication to the suppliers is another service, the agent needs to understand the imports to that country and the certification needed.
If you have to contact them the plus would be they speak English well, or have someone there that can.
Word of mouth can be the best way to find someone to help your buiness but not always true, as i have used quality checkers that are shown on Alibaba yet we had a bad time, so is best to start small and see what they can do, truth is in their work.
Some agents would take % for their work and others one payment, 50/50 payment is best and pay the last payment upon the B/L payment.
If you need to work with a new supplier you can get the agent to check them for you and give you their report, if you can visit China and meet the agent is always best for any business, but some people don't do this, if you want to start long term business is better to start as you mean to go on.
Make sure they have the basics use of computer and mobile phone, some people do use internet shops, and the need to be able to contact them when needed is paramount.
You need to have the person to work woth you and help your company and not just draw money.