Lots of oppinion, on jump starts. Even most manuals say find a good chassis ground, not to the battery. Good luck finding a good chassis ground, most every thing is covered in paint or preservative.
The safest way, I´ve found, is to hook up with both vehicles turned off. Try and start with just the battery, forget about the engine running and using the alternator. Leaving the batteries hooked up with a dome light or parking lights turned on, in the car with the dead battery, will help load the dead batttery somewhat (if it´s a healthy battery). On the old Delco SS type alternators, a run away regulator, was not uncommon and would often burn out every bulb in both cars, not to mention smoking the alternator and messing up the electronics. I´m not willing to trust the electronics in both vehicles to a voltage regulator.
As a side note, the OBD I computer is expensive and hooking up the jumper cables backwords, will sure enough kill it. The local auto parts stores, used to sell a bunch of OBD I´s, every time a ship would dock. They´d jump them, to get them off of the ship and the scortch marks on the battery lugs, attested to the fact they weren´t to careful about polarity.