China has a group called the Hope foundation. It is designed and targeted towards providing sustainable education to the rural areas via teaching, school construction, etc.
If you need help finding this national level charity group, drop me a PM (Private Mail) - but a simple google search should suffice to get your started.
Finally, if you google orphanage+kunming - you should be able to find one of the orphanages on the edge of town. I have the address and phone number (and a picture) if you're interested - but you'll have to approach them yourself (unless you can find someone to assist you).
EVERYONE there would graciously, gratefully, and excitedly welcome an english teacher (be sure to have an excellent retinue of singing and dancing curricula).
They can also use vision, dental, and healthcare checkups and maintenance, interesting western foods (american cookies, british biscuits, etc - nothing that could cause indigestion or food poisoning is best) - even foreign things like pencils, pens, erasers, pencil cases, backpacks (if you're financially loaded), toys (try to bring enough for each child), etc ad infinitum.
As always, talk to the school leaders beforehand and watch and listen carefully for their reactions, as they'll usually hesitate (out of courtesy) to tell you the truth (like exactly how many toys, clothes, miscellaneous goodies you should bring to distribute to each child, so no child gets left alone - bring spares just in case)...
Kudos to you and trust you will find an opportunity that is mutually rewarding and beneficial.