Generally Dreadhead, having the Cantilever Tube of the Tonearm level to the LP's Surface when the Cartridge is in the playing position is a good place to start with the PT-6, and generally any Tonearm.
To set overhand which is essential, You'll need some form of Cartridge Protractor, there are many from a cheap piece of paper, then up up to the Mobile Fidelity GeoDisc, (which is what), and then of course, one can go beyond, and things like the WallyTractor, are probably the best, But I think it's unnecesary to go to this extent with what you have.
Since there's no azimuth adjustment on the PT-6 Arm, (Tilt of the Headshell itself) this is one area you shouldn't have to concern yourself about.
Now onto Vertical Tracking Force, and Anti-Skating.
I've found that the provided Toneram adjustments on my own AQ Arm's Counterweightm and AntiSkate Control are pretty close, so first balance the Tonearm so that it's neutral (Balanced) in a level position hovering over the LP (Be careful here), Make careful adjustments clockwise/counter-clockwise on the Tonearm's Counterweight until this is achieved, then I return the Arm to its rest. Now carefully, without letting the counterweight turn on its shaft, set the circular slip dial at the front of the Tonearm to Zero. After this is done, then grab the rear of the Counterweight, and screw it in on its shaft to the desired Tracking Force Weight (ie: 1-1/2gms-2gms-etc)
It will be close, but I recommend at least getting an inexpensive Shure VTF Gauge.
Now to set the AntiSkate. Whatever your VTF force is, let's say 2 grams. set the little round Antiskate Knob to this same value. Provided nothing is broken on the arm, you'll be kind of close. If your vertical tracking Force is 1-1/2 grams, set the little Dial between 1, and 2. make sense?
A better method to achieve very close Antiskate Adjustment, will be with a Test Record which has an area with no grooves. The Hi-Fi News LP, or the Cardas Test/Demag LP is good for this. The final process is to test by ear, and a test LP can help in this regard also.
These adjustments should get you into some form of close Ballpark, and make the Arm usable without incurring damage to either Stylus, or LP.
As far as VTA, there's almost really no book you can look to for precise adjustment with any given Cartridge. This ultimately has to be done by ear.
Hope this helps, and if I missed spmething, please folks feel free to chime in. Mark