Also, check around your house thoroughly for baddies. I dunno about the other two, but I was rudely interupted by a conjurer who'd taken up residence nearby, while building Lakeview Manor.
The compass is a little tricky. You can't always trust it, but if you can't seem to find the option to buy the land from the Jarl, try the steward. And if the steward is dead, do the Civil War and get a new steward in place. If the steward is dead AND you've done the war, Talos help you.
If you're just starting this DLC or making a new character for it, collect every little scrap of Corundum, Iron, glass, straw, animal bits etc. Trust me, there's not enough materials between all the shopkeepers to furnish your house even half way, and the mounted creatures (wolves, bears, elk, slaughterfish, mudcrabs, horkers and goats) need to be constructed from the pieces. And for anyone having trouble general merchants sell straw, glass, and other furnishing materials.
If you haven't found out yet, you CAN make an anvil in the house and it's not a part of any of the wings, it's in the main hall, so you don't have to keep running outside to get nails and such. Same with the enchanting bench and the alchemy lab. So unless you actually want to have spires and a mage-oriented house, which is your prerogative, don't waste your resources on the towers. There's an area outside for planting anything of your choice (vegetables or ingredients) so the greenhouse isn't particularly necessary either.