Oh man, you are in for some rough stuff.
IF your spouce is well educated, income earning and solid in every respect, you should have no trouble getting a 10 year visa for her.
IF , on the other hand, she is poorly educated, unemployed and unknown, it is possible that the Consulate will make life difficult for you. They have suspicions of a "fixed" marriage. You know, "You marry me and I give you money>?" type of thing??
If the baby is declared at the local Oficial?a de Estado Civil, and then registered as yours at the US Consulate, he should be able to get a US Passport. He should also get a Dominican Passport.
Read the articles under this in the Archives...
Good Luck, be patient...
HB