Microsoft Press offers some free ebooks! I found the ebooks at Microsoft Virtual Academy (MVA) which offers online Microsoft training to help developers learn the latest technology. MVA is free of charge, and the entire service is hosted on Windows Azure.
One of the ebooks (1311 pages) is Programming Windows Store Apps with HTML, CSS, and JavaScript, Second Edition, by Kraig rockschmidt.
MVA has added 3 New Free ebooks. You can access them here.
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