Read this thread http://www.gamesas.com/topic/1408776-hearthfire-faqs/

If you did "rare gifts" and "kill bandit leader" and nothing happens, then there might be a bug. There are tons of threads on this.

Your a godsend, what do I do if the bug continues?

Nah, I started a new game with hearthfire and got the letter from the Jarl in Falkreath not long after I became the Thane of Whiterun - Dragon Rising etc. I never even set foot in Falkreath. I was at about level 8-10. It seems there's some sort of fame system - at least for new games (by fame, I mean there must be some triggers either when you reach a certain level or when you finish certain quests).

I didn't even have to give him a beer - in fact the option wasn't even there. I just had the option, hey, I got the letter, and he was all like: "yes, yes, it's you" blah-blah. He sent me to kill some orc leader, then I got to buy the land. Pretty straightforward.

No one from Dawnguard can be married, as far as I know. They added one character in Hearthfire that can be married, a Redguard woman, housecarl for Falkreath:

http://www.uesp.net/wiki/Skyrim:Rayya




*sorry everyone, I can't multiquote...

Are you people making sure you have the letter from the Jarl in your inventory? Also the Jarl doesn't give you the option to buy the land, thats the Steward dark Elf i think, after you do a quest involving killing a bandit chief in a mine near riverwood, forgive my bad english, i hope this helps, maybe it's too obvious, but you never know. I haven't experienced any bug or issue with Hearthfire, in fact i think it fixed a lot of stuff and somehow my game looks better now

The problem for me, I was thane of falkreath with Siddgier but then I did the DB quest to kill his housecarl Helvard. I did it in secret yet the Jarl is bugged out and put me to negative reputation with him, including not allowing me to purchase the plot.

I fixed it myself by joining the Stormcloaks which replaced the Jarl and Steward in Falkreath. I then regained my Thane title from Denegier and purchased the plot from the steward.

Looking forward for an UHFP (Unofficial Hearthfire Patch) coming soon after it's released on PC

Wrong. That's not how it works. You don't even have to set foot in Falkreath hold in order to get a letter from it's Jarl. Word spreads of your deeds.

Here's the prerequisites for getting the letter:

1) You have to be at least level 9.
2) You have to raise the disposition of a certain number of NPCs. Doesn't matter which hold they live in.

Tested extensively.

And if anyone's curious, here's the nature of my testing...

Started a brand new character after installing Hearthfire. Left Helgen and proceeded directly to Whiterun where I began to do favors/fetch quests for NPCs living there (Ysolda, Amren, Brenuin, Adrianne, Hulda, etc, etc.).

At level 8, I entered Arcadia's Cauldron just to sell some potions. While doing so, I gained a Speech increase which put me to level 9. Upon exiting her shop, the courier approached me and gave me the Jarl of Falkreath's letter. Out of curiousity, I reloaded from when I was still inside the shop, but this time I didn't level up. Stepped outside and there was no courier. Went back inside, leveled up, came back out, and there he was.

Reloaded a save from back when I first got out of Helgen. Didn't do favors for anyone at all this time. Just leveled myself to level 9 as quickly as I could just to see if the courier would still show up. He didn't.

Reloaded from that same save and went from Helgen straight to Riften. Did favors for various Riften NPCs. Got to level 9 and the courier turned up.

So it's "Level 9 + a degree of fame (anywhere) = letter from Jarl of Falkreath"

You don't need to have the letter in your inventory, but you do need to read it.

LB, thanks for taking the time for the valuable info! This should help a lot of the confused people.