I believe that I have a similar torque wrench.

The markings between 0 and 9 are for setting a torque between the main markings on the handle (eg. adds that many in-lbs to the nearest handle marking).

On the bottom of the handle should be a lock nut.

Steps:
1) unscrew lock nut so that it is loose
2) lets say you want 125 in-lbs of torque
3) turn the handle until the 0 lines up with the centerline at the 120 in-lbs marking
(you are now set for 120 in-lbs)
4) turn the handle (to the right) until the 5 lines up with the line down the middle of the markings
(you should now be set for 125 in-lbs)
5) tighten the lock nut on the bottom of the handle
(you are now set for this amount of torque)

However, typically I would set the wrench at about half (say 60 in-lbs), tighten all the nuts and then reset the wrench to the desired setting (say 125 in-lbs) and then retorque all the nuts.

For lug nuts, you should try to torque them in a criss cross pattern.


Gordon.