I lived in Suzhou, China in 2008 and did freelance work through oDesk. I found it worthwhile to always mention that English was my native language. Other than an initial interview, none of my work required telephone (Skype) communication so the timezone was not a factor. My first job on oDesk was only $8/hr as I just wanted to try it out but after that my rate jumped to over $20/hr and I never really had a tough time getting work. I have found going above $30 to be tougher to find work but then I haven't actively been looking for freelance work since being back. It should be a great experience for you!