1) Your local jurisdiction will have some manner of default will - a piece of legislation somewhere that says who gets what in the event that you die intestate. Look up a summary online. If its provisions bug you, you should probably get a will. If you're cool with it, then you don't necessarily need one. However, if you have an estate big enough that your relatives will sue each other for a piece of it(>$100k USD net worth, say), an estate that is somehow complex(trust funds, assets you want to go somewhere in particular, scumbag relatives you want to cut out, etc.), or children, I would advise getting one regardless. I know some estate lawyers, and the stories they tell are hair-curling. I know that's a biased source, because they don't see much of the simple cases, but it's an insurance policy I plan to get as soon as I have enough assets to be worth paying for it.

Also, when you're getting one, get a power of attorney set up. Most people don't do that even when they do get a will done, and it's a pretty ugly oversight if something goes wrong.