Anatole

A couple of questions if I may to those of you who are knowledgeable on the subject of long-term letting.  First, what are the main bullet points I should be aware of (e.g. definition of a long-let, language and jurisdiction of the contract, need for an inventory) and secondly, how do I become knowledgeable myself?!  Is it all just experience or is there a reliable source of information I can turn to?  It seems to me that there is any amount of info on buying a property but oh so little on the legal aspects of letting, yet the stakes are high if a long-let goes wrong!  Finally - how do people view long-lets in general - horror stories or useful sources of low season income?  Thanks, Anatole