I'm assuming you don't live near the land. What would security be like, against both human and animal predators? Would you be losing stock and produce or is the land beside the owners house? How would you cope at lambing/farrowing time? What is access like for feed deliveries and taking stock off for slaughter?
How would the cost (look at it per year) balance with the value of your produce, or is this not an issue? (if you look at what we pay for our smallholdings, it can rarely be justified financially, but more for its amenity value).
How many animals you can stock it with will partly depend on whether or not you use part of the land to grow fodder, or if you will be buying that in.
By renting you would have the option to leave if you don't like it, but equally the owner would have the right to kick you off if you fall out. What would you do with your livestock in this situation?
It is best to have a legal rental agreement drawn up for the benefit of both sides - if not there will be inevitable problems, no matter how much you like eachother at this stage.
Have a good dig around in the soil at various points to see just what you would be working with. Note also its height above sea level and any local climatic differences.