Once all the matters, financial/otherwise are settled between the parties, it is better to give an advance and write an agreement. This ensures that the owner does not change his word regarding the cost as well as make a sale to someone else who offers.

The property land can be registered in a sub registrar office, after preparing the title deed including all the relevant information. You could get the title deed written by a government licensed document writer. Even lawyers can prepare the deed, but the document can only be computer printed or typed, not handwritten. Handwritten documents can be prepared by only those who hold the scribe license. 

After registration, the registered document will be received after 2-3 weeks, from the registrar office.

The whole legal procedure of buying the property will be complete only if the new owners name is added in the village office records. An application can be made along with the copy of the registered deed to the Village office to get this done.