We just came back last month, we went to US with my maid, actually, you can visit the US embassy website, it's not very difficult, but you have to do many preparation. If you did all the preparation, (e.g. you have to prepare another contract just suitable for US, and check the minimum wages on the state you gonna visit, etc)and teach your maid how to answer the qustions for the US embassy's officer, the maid will get the visa for 2 years. Many maid was reject by them because the employer and the maid did not get the preparation very well, they are not critical but you have to do some homework (sound like a examination or interview), anyway, if you want detail information, you can pm me! Hope it can help!