How to Marry in Skyrim

Acquiring the Amulet of Mara

Travel to Riften. It's in Skyrim's south-east corner. You can fast-travel there by opening your map and selecting Riften. If you haven't yet visited Riften, you can instead pay a horse-drawn carriage outside of Whiterun (in the stables) or one of the other major cities to take you there. You may already have an Amulet of Mara if you've explored a few of Skyrim's dungeons. Be sure to check for it in your inventory before proceeding. If you have done the "Book of Love" quest, you would also have gotten the amulet.

Walk to the Temple of Mara. From the entrance to the city, go left and straight. On the left there should be a large temple with stairs leading up to it.

Find Maramal and speak to him. He's usually located in the Temple of Mara; if you arrive late at night, you may have to wait until noon or so the following day before he'll appear. If you still can't find him in the temple, he's most likely at the Bee and Bard pub, which is across the minor bridge in the middle of Riften.

Select the "I wanted to know more about the Temple of Mara" option. Maramal will respond by elaborating on Mara's lore. You can skip his dialogue by clicking the mouse button (or by pressing the A or X button on consoles).

Select the "I could have a wedding at the temple?" option. This will prompt Maramal to ask whether or not you're familiar with marriage in Skyrim.

Select the "No, not really" option. Maramal will explain how marriage works in Skyrim.

Select the "I'll buy an Amulet of Mara" option. This will require you to have at least 200 gold on you. As long as you can afford the amulet, Maramal will add it to your inventory.

Equip the Amulet of Mara. After doing so, you're ready to begin searching for a spouse.

Marrying

Find a person whom you wish to marry, then speak with them. People whom you can marry will express delight when you pass them or speak with them, but you can find a full list of marriage-eligible NPCs here: http://elderscrolls.wikia.com/wiki/Marriage. In some cases, you'll need to carry out a quest for your selected person before you can continue. If the person is a hireable follower, you'll likely just need to purchase their services. Gender doesn't matter. You can marry anyone that is listed as eligible.

Select the "Interested in me, are you?" option. The NPC will respond affirmatively.

Select the "I won't lie. I am." option. This will solidify the marriage agreement between you and the NPC.

Return to Riften. You'll be able to fast-travel there.

Find Maramal and speak to him. He'll be in either the Bee and Bard pub or the Temple of Mara.

Select the "I'd like to have a wedding at the temple" option. Maramal will respond by letting you know that the wedding will take place between dawn and dusk the following day.

Wait outside the temple until the following dawn. You can expedite the waiting period by pressing the "Wait" button (T on PC and "Back" on a controller) and selecting the appropriate number of hours from the current time until around 8:00 AM the following day. If you miss your wedding window, you must find your spouse and apologize to them, then set up a new wedding time with Maramal.

Re-enter the temple. This will trigger a third-person cutscene in which Maramal marries you and the NPC.

Select the "I do. Now and forever." option. Doing so will complete the marriage. If you have a house, they will live there with you.