Now that you own a house, you have to maintain it. To access Maintenance you click the Housing Management icon (the little house lower left in the radar) when you are in your house (or yard). Another way is via the character window. Scroll down or click here to read that.
Clicking the icon opens the Housing window. The first tab is the general info about your house.
Whose house is it, the address, and the costs.The Maintenance tab is where you pay the upkeep. You pay per week, but you can pay many weeks in advance.
The last tab is for handling permissions. Owner, Everyone and Kinship are there by default. You can grant personal permissions to a maximum of 50 people.
Accessing Housing Management via character tab
Open the character tab (Ctrl-C) and click House.
That opens a window similar to the one above. The only thing different is the Abandon button. Which speaks for itself, I think.