Everything about weddings in Russian

There are separate ways of saying married in Russian depending on whether you are talking about a man or a woman, which I suppose reflects the different status of the sexes historically.

She's married
A woman “walks behind her husband” when she gets married (выйти замуж за него), and “is behind her husband” when she is married (быть замужем за ним). This phrase is from the root noun муж, husband, and gives the adjective замужняя, adverb/predicate form замужем and noun замужество.
* Актриса Скарлетт Йоханссон вышла замуж за Райана Рейнольдса -Actress Scarlett Johansson has married Ryan Reynolds
* у неё очень счастливое замужество - she is very happily married.
* Ты выйдешь за меня замуж? - Will you marry me?

Traditionally, parents would give their daughter's hand in marriage (выдать замуж), but this phrase can be used more generally to consent to a girl's marriage or to arrange one.
* В минувшую субботу президент США Джордж Буш выдал замуж свою младшую дочь – Last Sunday, the US President George Bush gave his youngest daughter's hand in marriage.
* ХАМАС помог выдать замуж 100 палестинских вдов – Hamas organises marriage of 100 Palestinian widows

He's married
A man on the other hand, is “married off to (on) a woman”, or “wifed” (женить), from the noun женa. Historically, the groom might not have had much say in his choice of bride, but would be married off by his parents, and linguistically therefore, the groom is the accusative object of the impersonal verb женить and he is, literally speaking, married “on the bride”, eg.
* его женили на девушке, которую он не любил – he was married to a girl he didn't love

This phrase sounds old-fashioned now, and suggests he is married against his will, and in fact the phrase is used figuratively to mean exactly this:
* без него его женили means he was roped in without being consulted, as well as more literally he was married off without any say in the matter.
Женить can also mean to get someone to marry, persuade someone to marry, as in
* Как женить на себе мужчину – how to get your man to propose to you.

When you simply mean he got married, you use the reflexive verb жениться, which is also followed by на (+loc).
* Сын президента женился на актрисе – the President's son married an actress.

There is the adjective женатый, with the predicate short form женат, and noun marriage, женитьба, as in the opera Женитьба фигаро.

Marriage
The legal status of marriage is брак , and to get married in a legal sense is заключить брак. NB. this should not be confused with гражданский брак, which means cohabitation, or living together unmarried. Other related legal terms include брак по расчëту – a marriage of convenience.

To get married is also вступить в брак or сочетаться браком.

* Правительство разрешит японским геям сочетаться браком с зарубежными партнёрами. - The government will not allow Japanese homosexuals to marry their foreign partners.
* Астрологи советуют не опасаться сочетаться браком 09.09.09. По словам сотрудников загса, народ считает три девятки несчастливым числом. – Astrologers say don't be afraid of getting married on 09.09.09 (9 August 2009). According to registry office officials, people consider three nines to be an unlucky number.

жениться\по- and венчаться\об-/по- also mean to get married (said of a couple).

Proposing
To propose to someone is сделать предложение (+dat) or the full form сделать предложение руки и сердца – to ask for one's hand and heart in marriage.
* 17 советов как надо и как не надо делать предложение девушке – 17 tips on how and how not to propose

Getting engaged
Engaged to someone is помолвленный c (+inst), used for men and women.
* быть помолвленным с кем-нибудь - to be engaged to someone.
* Дима Билан помолвлен? Is Dima Bilan engaged?
* C кем он помолвлен? Who's he engaged to?
* Ни с кем я не помолвлен! I'm not engaged to anyone!

The verb помолвить, to betrothe, announce the engagement of, is very old-fashioned, but the reflexive form is used commonly:
* Мы помолвились!!! Я пару часов назад сделал Тане предложение! We're engaged!!! I proposed to Tanya a few hours ago!

The noun engagement, помолвка, refers to the time between getting engaged and actually getting married (время между предложением вступить в брак и бракосочетанием), but also has an official sense of announcing your intention to marry, as in “reading the banns” in the UK:
* обьявить помолвку - to announce an engagement
* Мы как-то без помолвки помолвились...We decided to get married without announcing it officially
* Помолвка не является обязательным процессом. Заключить брак можно и без помолвки. - Getting engaged is not a necessary stage. You can get married without first getting engaged.

The decision to get engaged is also обручение. Обручить (betrothe), like Женить, is old-fashioned and suggests parental involvement in the decision, but обручиться с (+inst), to get engaged, is very common:
* она обручилась с другим - she's got engaged to her boyfriend / she and her boyfriend have got engaged.
* Наследник испанского престола 35-летний принц обручился с 31-летней телеведущей – the heir to the Spanish throne, a 35 year old prince, has got engaged to a 31 year old TV presenter.

The Bride and Groom
Жених и невеста is a frequent title for wedding magazines and wedding websites. Note that in Russian it is normal to mention the bridegroom (жених) first and then the bride (невеста), whereas English puts the bride first. жених is also fiancé, and gives the (not very common) verb женихаться, to be engaged or going out. невеста means both bride and fiancée.

The big day
ЗАГС - отдел записи актов гражданского состояния - registry office

свадьба – wedding (the whole day)
бракосочетание – wedding, but specifically the official part, the signing of the registry (регистрация брака)
венчание – church wedding

обручальное кольцо-wedding ring
свадебный торт -wedding cake
свадебный наряд / свадебное платье / подвенечный наряд / венчальный наряд-wedding dress

Сongratulations!
поздравления с днем свадьбы! - Congratulations on your wedding day!

Here's some congratulatory lines of verse...

After the wedding...
Медовый месяц is an easy one, from мед – honey
новобрачные / молодожëны -newly weds
годовщины свадьбы – wedding anniversary
серебряная свадьба / 25-летний юбилей – silver jubilee (25 years)
Золотая свадьба / Пятидесятилетие свадьбы – Golden jubilee (50 years)
List of all the wedding anniversaries

Other links
Forum discussion about how to translate English phrase "in a relationship" -
Discussion about the pros and cons of living together out of wedlock - гражданский брак