I received my 64bit manuals from AMD today. I didn't think there was that much information on x86-64. Manuals are as follows:
Volume 1: Application Programming
Volume 2: System Programming
Volume 3: General Purpose and System Instructions
Volume 4: 128-Bit Media Instructions
Volume 5: 64-Bit Media and x87 Floating Point Instructions (CD-ROM included)
Each manual is about 500 pages in length and has good detail. Now I'm obligated to read these 2500 pages.