Were can I find free books, "young adult" books like Twilight or Tamora Peirce?

Well please no lime wire, I can't go to the library, the bookshop is a mile away so I'm stuck. Like I like all kinds of books, from the secret garden, to Twilight, to Wild Mage to the Clique. I'm kinda childish when it comes to books. So PLEASE HELP ME!!!