An answer for you all about the signs....
I really wanted to know the answer to these questions. So, I was sure to get them in one of my law classes. Here's what I found out. Having a sign is a good idea, because it warns the stupid people. However, you are not exempt from liability weather you have a sign or don't have a sign. Even if say, a guy named Bob got bit, and you had a sign up saying, "Bob, you are DEFINITELY going to get bit if you come in my yard.", and he got bit, you could still be liable. The assumption is that simply by having a dog, you KNOW and ASSUME liability, no matter what they do. Because they're dogs, and they could bite. Does that make sense?
You could have a twenty foot fence with signs on every square inch, and still be liable if someone climbed it and got in and got bit. Basically the thing to remember here is that dog bites are a CIVIL issue, not a CRIMINAL, so there are no hard and fast rules. Basically, the person getting bit would have to sue you. And then liability is decided by a judge or jury at the time, based on the specific circumstances.
I hope this helps. And, personally, I say hang the sign. It could prevent someone from getting hurt (either a stupid person or your dog) and it won't make you any more or less liable. However, since often a jury decides liability, it could make a jury feel more sympathetic to you if some dumb-@$$ gets bit in your back yard.
