How do i file taxes separately from my wife, who is a nonresident alien? she doesnt have a SSN. how do i fill out the form without this?

Your wife needs either a social security number or an Individual Taxpayer Identification Number (ITIN) for you to file either Married jointly or Married separately.  Here is a link that explains.  The other potential option, if you have a qualifying dependent, is to file head of household.  

For information on how to get an identification number for your non-resident alien spouse use this link.  

In order to file your tax return and W7 simultaneously you will need to enter and "fake" social security number for your spouse into to TurboTax.  You will need to print, sign and mail in the return to the special address in the link above.  Before mailing the return you will white out the "fake" social security number you entered.  It was only there to allow the printing of the return.