I just recently switched to Madness and had to redo my layout from Deception. The layout I use is due to doing an even mix of pvp/pve. I thought about it logically and figured for my most used buttons I'd map them to my pointing finger. That way I could strafe(A/D) and use the mouse buttons to run through ppl all whilst performing attacks.
My rotation is DF, CT to close the distance then Discharge(Moar Dots) and watch for CT/Maul procs. Rinse repeat and I have my CD's mapped to mouse buttons 3 and 4 for ease of use since I'm popping these every CD. My layout is as follows.
F - Death Field
B - Creeping Terror
4 - Discharge
T - Creeping Terror
R - Maul
G - Assassinate
2 - Thrash (need for CT proc, can still strafe and run through ppl)
V - Shock
5 - Stun
Misc.
I also use Q, E, Z, X, 1, 3 and shift modifiers of Q, E, R and G. These buttons are not affecting damage so put what you feel works best for you. Best to map them out and run some pvp to get used to it in action.
Hope this helps.