I think the first issue is not where to save and how much to earn,

it is not easy to open any account without a US SSN number. Most banks will not open accoun without SSN. Some may will, but will hold a large sum as tax.

If he can find a way to open accounts, here are some suggestions (my 2 cents only):

See how much total he has. My rule is: the more money, put more on some risk bearing places, such as MF or stocks.

For banks, usually it can get >=5% APY return before tax.

See here for a list of them: http://www.huaren.us/dispbbs.asp?boardID=336&ID=267857&page=1

For MF, see here: http://www.huaren.us/dispbbs.asp?boardID=336&ID=256217&page=1

If it was me, I may put aside first 1-2 years cost in banks, then the rest in MF.

Of course, MF has risk of losing money.

Also be careful, US$ is losing value and ChineseRMB is gaining.