Orion Press has some interesting articles concerning Warp velocities in their Articles section: http://www.fastcopyinc.com/orionpress/articles.htm
They also have this nifty Warp calculator program, which compares the Orion, Warp Cubed and Okuda/TNG scales: http://www.fastcopyinc.com/orionpress/warpcalculator.exe
They also have this nifty Warp calculator program, which compares the Orion, Warp Cubed and Okuda/TNG scales: http://www.fastcopyinc.com/orionpress/warpcalculator.exe