I would strongly recommend hiring a site supervisor who has knowledge in construction (preferably farming as well). It’s also recommended to give contract to various works like centring, masonory etc. Depending upon the size of the project you would also need daily labor. You would need to find local workers and fix labor costs. You must supervise almost daily to ensure that quality work is being done and reduce cost overruns. Be prepared to shell out additional 15% to 20% above your budget unless you are ameticulous planner.
I have been building a farm house, cow shed with caretaker room and a water tank (above ground) with fence, road etc. I have planted close to 600 tree and fruit saplings as well. I have been “photo documenting” the entire process which I can make available to you and also provide email support so you are equipped with knowledge. Your experience on the ground may be different from me but at least you will be knowledgeable enough to deal with day to day issues. All the best.