Overview Nothing in life stays the same, a realization that sometimes dramatically dawns when you go from being single to being half of a wedded couple. Successful transitions to marriage call not only for changing your mindset from "me, myself and mine" to "we, ourselves and ours," but also for ensuring that you've filled out the appropriate documentation for your new union to be recognized as a legal entity.Legalities Marriage is a contract between two consenting adults, so it generates a bounty of paperwork. If the bride changes her last name to her husband's, she needs to get a new Social Security card, driver's license, bank account and credit card in her new name. Even if there is no name change, both the husband and wife should let their insurer know, and they might need to change their bank account information, beneficiary and tax filing status. Nihara Choudhri, author of "What to Do Before I Do," cites the rising popularity of prenuptial agreements as a way to protect each partner's assets in the event of divorce.Cohabitation Most married couples live in the same house. If you have not been living together before marriage, married life suddenly exposes you to lifestyle quirks you probably never noticed during the courtship phase, according to Peter Scott, author of "There's a Spouse in My House: A Humorous Journey Through the First Years of Marriage." Maybe you don't like his ugly beanbag chair, and maybe he hates the New Age art you bought at a flea market. But marriage is about understanding--and accommodating--the importance these items have in your lives. It also requires you to adjust your previous territorial rights to the bed, the closet space and the bathroom cabinets.Finances When you lived by yourself, you controlled your own purse strings. Once you marry, your income becomes part of a pooled resource, according to Caroline Tiger, author of "The Newlywed's Instruction Manual." During the newlywed phase--or, preferably, before the wedding ever takes place--you and your spouse need to figure out who will be accountable for which bills, whether you'll maintain joint or separate bank accounts, and how you'll build your savings toward goals such as a home, vacations, your children's education and your retirement.Conflict Resolution Being able to negotiate fair outcomes for both sides in a disagreement is critical to a healthy marriage, according to Carley Roney, author of "The Nest Newlywed Handbook: An Owner's Manual for Modern Married Life." When you were single and had an argument, you could refuse to answer the door or the phone. You could even pack up and move away. When you're married, however, the flight syndrome is no longer an easy option because you both have far more of yourselves invested in the relationship. Marriage requires you to not only rethink your communications skills but to respect that your partner has an equal say in the present and the future.Decision-Making Spontaneity might have been the operative word in your calendar as a single. You could stay out as late as you wanted or take road trips at the drop of a hat. When you marry, you need to consider your spouse's wants, needs and expectations. You're now a collaborative team, Scott points out, and you need to discuss everything from chore division to major purchases to holiday dinners with the in-laws.