How do I buy a plot of land in Skyrim Hearthfire?

Question

where do I go to buy land in Skyrim Hearthfire DLC?

Answer 1

See here:

Skyrim Hearthfire Walkthrough - Buying a plot of land

Answer 2

I was approached by a courier in Falkreath that told me to visit the Jarl's steward to purchase a plot (the one in Falkreath is called Lakeside Manor).