<p>It's probably easiest to link you to this question on Meta Stack Overflow which explains the process.</p>

<p>I'm not 100% certain it'll delete all your questions or whether they become owned by the Community user.</p>

<blockquote>
  <p><a href="http://meta.stackexchange.com/questions/5999/can-i-delete-my-account">Can I delete my account?</a></p>
</blockquote>