Is there any law about Severance Agreements or website I can refer to?
Someone also mentioned to me that in CA - company is required to give an employee at least 10 days to review the document?
Is that correct?
Thankyou.

Though the review period is not a factor in a law, regulation, etc. most employers recognize that an employer should give employees sufficient time to review the document and discuss it with attorney. Otherwise, the agreement could be viewed as being invalid.

I'm not sure what issue you have regarding severnce payment. Can you be more specific so I can point you in the right drection?

There is one federal law calling for severance. It is called WARN. You can read about WARN at: http://www.dol.gov/dol/compliance/comp-warn.htm