There are hundreds of books about search engine optimization for sale online right now -- most of them are garbage.  Some are full of outdated information, some are packed full of tactics that don't work, and some are just plain silly.

I came across a book today that is packed full of excellent SEO information and, even better, FREE.  It seems odd that this book is 10X better than other books that cost $97 or more, but it's true.  Right click here and "save target as" to download the PDF file to your hard drive.