[bane]

If you're interested in Sci-Fi, especially some of the older stuff, there's an unbelievable treasure trove of books, short stories, scanned magazines, old radio dramas and books on tape all for free at archive.org.

Finding stuff there is a mess though, but even just a search for "science fiction" is like falling into a dragon's hoard of genre pieces.

[tjradcliffe]

Also lots of free stuff at Project Gutenberg, including a bunch of Astoundings (which I believe is what Amazing Stories became?): http://www.gutenberg.org/wiki/Science_Fiction_%28Bookshelf%2...