How long do we need to wait before my boyfriend and I get married and file a petition after his divorce?

You have asked three questions. One how long should you wait to marry after your boyfriend's divorce. Answer, for your new marriage to be valid, you can marry him the following day after the judgment of divorce is signed by the civil court. Next, you also inquire how long you should wait to file his paperwork, Answer, you can file the I-130 petition immediately after your marriage. Your third question relates to the kinds of documents necessary to convince DHS of the bona fides of your marriage. Answer to that will depend on the nature of your relationship. But note generally that anything that goes to show that your marriage was entered into in good faith and not for immigration purposes should be brought to the attention of CIS. The agency has a well developed fraud profile which includes amongst other things for instance, the time and sequence of marriages and divorces to weed out sham marriages entered into for immigration purposes. But note if CIS determines your marriage is questionable, how early or how late you marry or file the paperwork will not convince CIS otherwise. Given the dire consequences of a fraudulent marriage determination, I urge you to consult with an experienced immigration lawyer.

You can get married as soon as the divorce is final. If the marriage is genuine, you can apply for a visa immediately.

There is no minimum time you have to wait to marry after his divorce is finalized. As far as proof of your marriage, that will be something you should discuss in consultation with an immigration attorney and you can start gathering the documentation once you are legally married. If he is abroad, you can also petition for him as a fiance and he can get a visa to come to the US to marry you and then file for a green card.

In Florida a party may remarry 24 hours after the divorce is final. I cannot comment on immigration issues as I do not handle those matters.

There is no legal requirement that you must wait a certain period of time before you can petition for your husband. You can file the I-130 petition for him as soon as you have been legally married. The marriage can take place immediately after his divorce has been finalized by the court. To establish that your marriage was done in good faith and not for the purpose of circumventing immigration laws, you can submit any evidence that would reflect on the validity of your marriage, including but not limited to, evidence of regular communication (phone records, letters, emails, etc.), photos taken together, birth certificates of any children born to the relationship, evidence of cohabitation (leases, mail received at the same address, etc.), evidence of commingling of finances (bank accounts, tax returns, receipts for major purchases, health/auto insurance, joint ownership of properties, etc.), and affidavits from people who have personal knowledge of your relationship.