Outside the cave you can find Lavender and some Tundra Cotton. When you go inside, enter sneaking. There is a high-level Vampire inside (like a Vampire Nightstalker) with a number of Skeletons they can reanimate. Deal with the undead then head to the Southeast corner of the room. You will find a locked chest (Adept level) there. Open it up for some loot. Now head over to the West wall and climb up the Southwestern stairs. This is the one passage through to the second room. Take some time to heal up and recharge your Magicka and stamina, there is a Boss Vampire in the next room.
The Master Vampire can be anywhere in the room. be sure to look around for them. Engage at a distance and close it quickly. Remember that they are weak to Fire Damage.
When you have dealt with the Vampire Boss, it is time to search the room. You can find a rare Black Soul Gem sitting on the small bookcase by the arcane enchanter. You can also find the Illusion skill book: Mystery of Talara, Part 4 on that same shelf. It sits in the bottom right. On the arcane enchanter is a random enchanted sword. Move to the left now. On the next bookshelf you can find Frost Salts, Vampire Dust. Look to the right of the passage you came through. You will find an Alchemy Lab. Sitting on that table is the Lockpicking skill book: The Wolf Queen, v1. A healing and a magicka potion can be found on the table as well. There is also a vial of poison available there as well.