I've noticed a lot of confused people on the interwebz about the new skyrim hearthfire DLC. To help clear this up I've compiled some of the most common questions that have been asked and I will answer them to the best of my knowledge.
Q: I downloaded the new DLC but nothing is loading when I go into my game and no courier is coming to me. Why?
A: if you downloaded it from within the start menu, you must go to your dashboard and re-load the game. The easiest place to find the courier is in whiterun.
Q: how come I only got 1 letter from the courier about upgrading my breezehome or adopting a child, but not about where to go?
A: this seems to be one of the minor glitches in the game. Don't fret, as all of the DLC content will still be available to you.
Q: where do I go to get the land deeds and how much are they?
A: the 3 towns are morthal, falkreath, and dawnstar. You must talk to the jarls steward and they are 5000 septims each.
Q: the jarls steward(s) won't give me an option to buy land. What gives?
A: as with being able to buy a house in any other town, you must do a favor for the jarl or become thane.
Q: it doesn't show where my plot of land is on my map. Did I even buy anything?
A: yes, don't worry. To find your land, look under the "misc quests" tab and select it, then select your misc missions. It will plop an arrow right where you need to go.
Q: can I put the land anywhere I want?
A: no. All three are predetermined for you.
Q: where are the quarry and clay deposits, sawn logs, and glass and straw at? And where do I get the building materials like nails and hinges?
A: quarries and clay deposits are within a very close proximity to the house. Quarry is a very light grey with white lines (similar to normal ore deposits) and clay is a brown/maroon color on the ground. Sawn logs can be purchased from any saw mill owner. They are 200 septims for 20 logs. Glass and straw can be found in general goods stores only (if you've played oblivion, it's similar to buying furniture), and every once and awhile, out in the wild or caves/dungeons. They will also sell child's clothing and toys. The other building material can be made at an anvil (usually next to the carpenters table) or any smithing pit (can think of the name, drawing a blank). They all take iron ingots and locks take an extra corundum ingot to make. You will make 2 hinges per ingot and 10 nails per, where everything else is 1:1 ratio.
Q: how can I make someone my steward?
A: some followers will be made into stewards once you create the "main hall" part of the house. Bring a follower to the house and they will ask if you want them to be your steward for that house. Not all followers can do this, mainly townsfolk like faendal, and for the most part, no warrior type followers.
Q: what kinds of things can I make for the house?
A: there are 3 options per wing, and 3 wings per house. 3 of the options are for a more homey feel like bedrooms and kitchen, while others can be for the warrior or Mage, like the armory or enchanting wing. Since you have 3 houses, you are able to mix and match what you want.
Q: how do I buy a horse for the stable and animals for the pens?
A: talk to your steward and select "I want to upgrade the house". You can buy a horse, cow, chickens, carriage, and a bard. You can also give him money to buy upgrades or make renovations in your home.
Q: I want to start adopting kids. Where can I find them?
A: the orphanage in riften has a big selection, but each city has a few kids running around after dark that you can adopt. A good time to find them is around 1-2 am when everyone's asleep. Talk to them and you will get the option to adopt them.
Q: how can I find toys for the kids?
A: some toys, like dolls and wooden swords, can be found while dungeon diving. Others can be found in the general goods store after you adopt kids.