I performed my first JTAG on a Xenon Xbox 360. : r/360hacks
How to JTAG Your Xbox 360 and Run Homebrew : 10 Steps (with Pictures) - Instructables
Amazon.com: ASHATA TX Programmer V2 for Xbox 360 Game Console, NAND for XILINX CR JTAG Programming, for Xbox 360 Mainboard Cable Repair Tools Set for CoolRunners inc, Phat and Slim, etc :
How To R-JTAG your Xbox 360 ! - Part 1 - The Basics ! [HD] - YouTube