You must meet certain requirements in order to marry. These vary slightly from state to state, but generally include:

• being at least the age of consent (usually 18, though sometimes you may marry younger with your parents' consent)
• not being too closely related to your intended spouse
• having sufficient mental capacity -- that is, you must understand what you are doing and what consequences your actions may have
• being sober at the time of the marriage
• not being married to anyone else
• getting a blood test (in just a few states), and
• obtaining a marriage license.

Yes. In May 2004, Massachusetts began issuing marriage licenses to same-sex couples who live in the state, and California allowed same-sex marriages from June through November 2008. Connecticut begain issuing marriage licenses to same-sex couples in November 2008, and Iowa did the same in April 2009. Vermont followed suit in September 2009, and New Hampshire offers same-sex marriage beginning in January 2010. Many other states have passed laws specifically barring same-sex marriages, and the number of states with such laws is increasing. However, there are states that allow same-sex unions that are similar to marriage.

In California, domestic partnership creates a marriage-like relationship in which same-sex partners have nearly all the rights and responsibilities of spouses (and partners who are married may also register as domestic partners in California if they wish). Connecticut, New Hampshire, and Vermont offer civil union registration for same-sex couples, who can register their partnership and receive all the benefits of state laws that apply to married couples. The District of Columbia, Nevada, New Jersey, Oregon, and Washington State have domestic partnership that also is equivalent to marriage. Colorado, Hawaii, and Maine all have some form of registration for same-sex couples, with varying levels of benefits -- but none are marriage equivalents.

For more information, see Nolo's article Same-Sex Marriage: Developments in the Law. For guidance on whether to enter into a marriage or other legal relationship with your same-sex partner, see Making It Legal: A Guide to Same-Sex Marriage, Domestic Partnerships & Civil Unions, by Frederick Hertz with Emily Doskow (Nolo).

A marriage license is a piece of paper that authorizes you to get married and a marriage certificate is a document that proves you are married.

Typically, couples obtain a marriage license, hold the wedding ceremony, and then have the person who performed the ceremony file a marriage certificate in the appropriate county office within a few days. (This may be the office of the county clerk, recorder or registrar, depending on where you live.) The married couple will be sent a certified copy of the marriage certificate within a few weeks after the marriage ceremony.

Most states require both spouses, along with the person who officiated and one or two witnesses, to sign the marriage certificate; often this is done just after the ceremony.

Usually, you may apply for a marriage license at any county clerk's office in the state where you want to be married. (In some circumstances, you must apply in the county or town where you intend to be married -- this depends on state law.) You'll probably have to pay a small fee for your license, and you may also have to wait a few days before it is issued.

In some states, even after you get your license you'll have to wait a short period of time -- one to three days -- before you tie the knot. In special circumstances, this waiting period can be waived. If you wait too long, your license will expire. Licenses are good for 30 days to one year, depending on the state. If your license expires before you get married, you can apply for a new one.

For more specific information about marriage license laws in your state, see Chart: State Marriage License and Blood Test Requirements.

A handful of states still require blood tests for couples planning to marry. Most do not. (For information on which states require them, see Chart: State Marriage License and Blood Test Requirements.

Premarital blood tests check both partners for venereal disease or rubella (measles). The tests may also disclose the presence of genetic disorders such as sickle-cell anemia or Tay-Sachs disease. You will not be tested for HIV, but in some states, the person who tests you will provide you with information about HIV and AIDS. In most states, blood tests can be waived for people over 50 and for other reasons, including pregnancy or sterility.

If either partner tests positive for a venereal disease, what happens depends on the state where you are marrying. Some states may refuse to issue you a marriage license. Other states may allow you to marry as long as you both know that the disease is present.

Non-religious ceremonies -- called civil ceremonies -- must be performed by a judge, justice of the peace, or court clerk who has legal authority to perform marriages, or by a person given temporary authority by a judge or court clerk to conduct a marriage ceremony. Religious ceremonies must be conducted by a clergy member (priest, minister, or rabbi). Native American weddings may be performed by a tribal chief or by another official, as designated by the tribe.