A great starting point would be to drop a plumb bob from the center of the front motor mount stud that extends below the front cross member (make sure it is equidistant from each side rail) and measure to the outer edge of each rear axle/nut. Then hang another plumb bob from the rear/center of the rear end housing and measure to the bottom ends of the front king pins. (you may want to drop plum bobs from these locations as well and measure along the floor.) If these dimensions at each end are not the same, it will give you an idea as to where to start with the corrections. Follow Brent's advice for how to correct your issues.
I am not of the opinion that any toe in setting will result in 'dog tracking'. This condition will be present if the dimension from the front motor mount to the rear axle nut is not the same for both side.