feel free to correct me.
1）You (at USA) file i-130
2) After CIS approves your I-130, it will forward the case to NVC (National Visa Center). You (at USA) will receive the fee bill and Affidavit of Support (I864 和DS-230) from NVC, and you send them back with a check
3) NVC will mail Packet 3 to your parents in China (领馆会以中文地址寄出通知给父母, 送NVC的一份表里,填过中文名字和地址 )
4) Your parents (in China) do their part in the above forms and mail it to you (at USA), and you finish the rest of the forms and mail it the NVC.
5) NVC 会把你父母的材料转到广州领事馆,就要再等半年左右,你父母在国内可以收到面签通知,同时会寄给他们I230表的第二部分,要填好带去,(Packet 4), (在面签前他们要去体检,打指膜.)
(这来来回回的表好象他们--parents--都要签名的,我是寄来寄去好多次的)