You have to contact your consul and ask for a new passport. After you get a passport, you can marry; the city clerk will not ask you for a proof of your legal immigration status. To obtain a green card after the marriage to a U.S. citizen, you would need proof of legal entry into the U.S., in other words, a copy of your H1B visa and Form I-94. The U.S. Government has these documents, and you can obtain them under the Freedom of Information Act. You can try doing it yourself; but, since retaining an attorney to handle your legalization process would be a good idea anyway (considering your immigration violations and prior marriage), your attorney will request copies of your entry records. Considering that obtaining the records takes very long time (9 months to a year is not uncommon), you might want to start the process as soon as possible, without waiting for a passport and a marriage certificate.
Answered on Dec 02nd, 2012 at 9:52 PM