afc hack what kind of resistors to get?

i have dsm 450cc injectors and i need to get inline resistors for them for the afc hack of course.

What resistors do i need? 10ohm 10 amp onse or 10ohm 10watt ones from radioshack?

Also do they just intercept the main power wire to the injector and the negative is left alone?

Any help is appreciated thanks