.If a company really does need you, you can work for them but you wont get paid, until you get ssn.
Actually, a company will pay you, but withhold taxes at the highest rate (which comes out to about 30%). If they didn't pay you, it would be like them assuming you would pay 100% in taxes.
Once you get your SSN, and then file taxes, you will get a nice Refund
BTW, this is stated on a form that you can get from SSN. It tells you that you can work even if you don't have the number, and what percentage your employer must take in the meantime.