Packt publishing currently has a promotion of reducing the prices of books to $5 USD if a purchase of 2 or more is made. Books such as a Computer Vision cookbook, costing $22 USD, will be on sale for $5, good deal IMO.
This company offers books that tries to keep up with the latest technologies and paradigms of software engineering. They have many books on HTML5, the current trend of technology right now. I suggest browsing their collections every few months/weeks to see what is new.
Visit their promo page for more details: http://www.packtpub.com/news/stock-your-reader-christmas