How do land contracts work?

If the house you considering to do land contract with has a mortgage in someone else`s name and you are paying the taxes who writes it off on taxes?

In the case of a Land Contract, the bank is the owner. The tax write off is the buyers. Your lender should be able to help you with the forms. Or the title company will help with that. If you are entering into a Land Contract; its different than a lease/purchase. Some people get them mixed up.
The land contract is a legal and binding purchase and should be notorized with a title company. The terms and conditions should be drawn up with a realtor or a 3rd party witness (attorney). Every one should receive copies of the paperwork. You would then turn that over to your accountant before tax day to prove you are purchasing the property. This should also be registered at the court house. It should work out from there... to your advantage.