This is a really good one, but I don't think it's available for download: http://www.tuxradar.com/practicalphp
What do you want an eBook for? Beginners tutorial I assume? I don't know of any good eBooks but this is a truly fantastic book for PHP beginners, its getting a bit old now but will give you a solid introduction of procedural PHP. http://books.google.co.uk/books/about/PHP_5_in_Easy_Steps.html?id=ErAxAAAACAAJ&redir_esc=y Thanks Andrew
Search by isohunt, or pirate site,or from Google, you can get more and more books, orally beginning php is very good books.
there are some good Rockable Press books on PHP but if you're going the ebook route I'd suggest checking out some of Jeffrey Way's screencasts on tutsplus. Well worth the investment for a beginner. Disclaimer ( I haven't watched all the php ones, I knew PHP well before he made them but I briefly checked them out and they look solid. His screencasts and tutorials have helped me immensely with ruby and vim though.) Highly recommended.