I briefly mentioned about free DX10 book available on GDWiki. I am still reading this book whenever I have free time, but I can't really read it fast, because without being properly edited, some sections of the book are really hard to read.
But I found really useful information in this book: performance comparison of different lighting models. Also, it comes with actual shader code examples. Especially it was interesting to see Cook-Torrance, which does both diffuse and specular lighting, is faster than the combination of Blinn-Phong specular and Oren-Nayar diffuse models.
Take a look at this page for more details.