I thought I'd post a bit about the details of land claiming.
To claim land, you need the Yeomanry skill, which costs 4000 LP. With it, you can build a claim stake (the totem-pole like thing) from the Adventure menu, which will claim an area of 5x5 tiles around it. Once built, you can expand the claimed area by paying 10 LP per tile. Land is always claimed in rectangular shapes, and it is impossible to claim land closer than 5 tiles to already claimed land. It is designed with those limitations to ensure that it is impossible to "enclose" land with claims. It ensures that passage between claims is always guaranteed.
Right now, it works such that people in the same party as you can walk on your claims. In the future, I intend to expand it with options to allow passage to the alternatives of 1) only yourself, 2) people in your party, 3) people on your buddy list and 4) anyone. I'd also like to add an option to make some buddies "trusted", and add an option to allow only trusted buddies to walk on the claim. There should also be separate options for allowing the manipulation of items on the claim to the same groups of people.
It should also be mentioned that animals do not random-spawn on owned land.