Hello Townski, I'm new to simulation games and at the moment I'm also using an Xbox controller with the temptation to buy a steering wheel getting bigger every day.
Regarding driving, being the most intuitive for me, my configuration is:
Left Trigger: Brake
Right Trigger: Throttle
Left Bumper: Clutch (Set to automatic, since it is only a button we cannot regulate the pressure).
Right Bumper: Neutral
X: Gear Down
A: Gear Up
B: Handbrake (Doesn't seem to have any effect, if someone could help us...)
Y: Turn on/off lights
Right Stick: Steer
Pause, car respawn, camera, LCD, MoTeC and rear-view mirrors are distributed between D-Pad and the rest of the buttons.
All sensitivities at 0%, except speed sensitivity at 50%. No dead zones.
Sorry my bad English!