Besides adding a ton of new weapons, items, quests, and shouts; Dawnguard adds in a whole new slew of people, places, and creatures to Skyrim. With so many new places to get lost in and names to remember, you would practically need a guide just to keep it all together.
We thought we'd give you all a little primer before you go exploring.
Durak the Orc -- When you first encounter the Dawnguard, Durak will seek you out, a skirmish will break out with new Vampires, and he'll tell you about the vampire hunters. Ask him about them, and he'll point you in the direction of Fort Dawnguard.
Galathil -- You can find her in the Ragged Flagon in the Ratway beneath Riften. Give her 1000 gold, and you can re-edit your character's appearance.
Lord Harkon -- The Leader of the Volkihar Vampires and your ultimate target as a member of the Dawnguard.
Serana -- This lovely lass just happens to be Vampire Lord Harkon's Daughter. You discover she's been locked away for a very, very long time in the quest Awakening.
Isran -- The leader of the Dawnguard in Skyrim. You'll be talking with him quite a bit as a member of the group.
The new locations of Dawnguard:
Fort Dawnguard -- The home fort for the Dawnguard. It's located way to the South East of Riften. I recommend traveling to Stendarr's Beacon then setting out from there to find it. Once you have access to the Fort, be sure to explore it before leaving. There are a number of containers, and you could probably find some useful loot. As you progress on the Dawnguard side, the Fort gets more and more upgraded.
Castle Volkihar -- The Vampire Lords' Home Base of operations. For Vampires, it has everything you could want: coffins to sleep in, enchanting tables, alchemy tables, plenty of gear, plus human "cattle" for you to feed on without anybody reporting you.
Dead Drop Falls -- Located through the cavern in the back of Fort Dawnguard. Drop down the Waterfall, and explore the massive cavern. You'll need a crossbow to really explore it.
Dimhollow Crypt -- The location of the second quest. It can be found just North of the Lord Standing Stone. Undead dungeon, filled with Vampires and Draugr. The Draugr and Vampires don't like each other, so feel free to let them thin each other our if you get the chance.
The Soul Cairn -- You'll head to the land of the soul trapped during the quest line regardless of which side you pick. While there, you'll have to rely on the local map for your bearings. It's really easy to get lost here since there's not a lot of different scenery to help you visually.
Look for the Massive Wall -- This wall separates the two halves of the Soul Cairn if you get really lost. There are a few little things you should look for too. Lightning Attractors will turn Greater or Grand Soul Gems into Black Soul Gems. Jiub's Opus is broken into 10 pages that you can track down and return to his soul for a unique Necklace. And of course, you can find Arvak's Skull to earn your undead horse.
The Forgotten Vale -- A massive valley far in the North West of Skyrim. You'll visit her during the quest to track down Auriel's Bow. There's a ton of things to look for here: the Jewel Paragons, the Word Wall for Drain Vitality, two unique dragons, and a large number of Falmer, many wearing the new Hardened Heavy Armor. Clear out a lot of space, or trek back here a few times if you want to get it all.
Arkngthamz -- A dwarven ruin you'll visit for one of the side quests called "Lost to the Ages." It's located just a little southeast of Markarth. You'll find a unique Dwarven bow, plus an Aetherial Shard, related to the quest. Once you grab this one, you have to go track down three more in different Dwemer Ruins and then find the Forge. Happy Questing!
New Creatures and enemies in Dawnguard:
Armored Trolls -- As a member of the Dawnguard, you'll be able to buy an Armored Troll to follow you around and help out.
Bonemen, Mistmen, and Wrathmen -- While you're in the Soul Cairn, you'll encounter each of these guys. They are basically a black, semi-unique, undead set of enemies.
Boneyard Keepers -- A sort of boss-like enemy in the Soul Cairn. You'll need to kill three of them during the quest there. They're huge, and they wield Dragonbone weapons.
Chaurus Hunters -- A new, winged variant of the Chaurus. There are regular hunters, as well as fledglings. They have decent poison attacks, so be a little cautious.
Death Hounds -- Vampire pet attack hounds. There’s nothing really to worry about, unless you're really low level.
Frost Giants -- Only found in the Forgotten Vale. You’ll need to kill these stronger giants that carry the special Jewel Paragons. As with all giants, prepare for a tough fight.
Gargoyles -- As a Vampire Lord, you'll be able to learn how to summon these guys to fight with you. As a Vampire Hunter, you'll be fighting them instead. They're tough, but they drop some nice gems and ores.
New levels of Dragons and Falmer are also added. Dragons go up to Legendary, and Falmer can become Warmongers now.
Sharpen your blades, prepare your arrows, make sure you have potions and magicka, and set out to explore the new additions to Skyrim!