StartupNation has a great Q&A about sourcing manufacturing from overseas, with an emphasis on China.
We've been involved with mulitple small businesses that have used Chinese contract manufacturers and based on their experience the information in this article looks solid.
One point that I would quibble with is around intellectual property. From what we''ve seen and heard, the IP problems are greater than this Q&A suggests. If you are going to manufacture in China, you need to be very careful with your IP.
Another important point is it doesn't always make sense to use a Chinese, or foreign, contract manufacturing facility. We've seen a number of examples of companies bringing manufacturing back to the US.
The firms choosing US contract manufacturing facilities tend to make relatively small numbers of products with short life cycles. The reasons they moved back to the US are (1) faster turn around times, (2) the ability to more easily interact with the production team on design adjustments and changes, (3) cheaper freight (especially for those using air freight) and (4) safer IP.
But if your product volumes are high and life cycles long, offshore manufacturing makes a lot of sense. And with the help of good agent (see the Q&A), it is surprisingly easy.