My daughters father is dead and died when I was 5 months pregnant so there is no way to do a dna to tell she is his and his name is not on the birth cirtificated and my soon to be husband would like to adopt her as his and I would like to know what I have to do

You marry this man stay married for 6 months to one year then seek to file for step parent adoption

1. Get a lawyer
2. Get married. Most states won't allow a stepparent adoption until you have been married a specific amount of time (usually a year).
3. Establish paternity--you're going to HAVE to prove that the biological father isn't around to have his rights removed. That means you have to PROVE that the father of your child is actually the deceased man you are claiming it is. You can usually do so through family members.
4. Go to court to file adoption papers.

Yes paternity can be proved by DNA but by waiting t is a lot more difficult. Another thing is you should have put his name on the borthcertificate if you were sure he was the father. Also your child may have been entitled to SSI.