Overview-- Ran undergound conduit from polebarn to home. Ran #4 black(power)#4 Red(power)#4 White (Neutal) #8 Ground. Going to use polebarn for general lighting/outlets, but possible later might use a welder, that's why I ran the extra power lead.

Going to wire polebarn panel first, to a 100 amp main breaker. In addition going to wire 1 working outlet under box to verify working outlet and voltage.

Then shut down main breaker in home. Wire neutral/ ground/ and both power leads to a dual throw 100 amp breaker. Turn on main breaker in home, then energize breaker in polebarn, check for voltage.

Does this sound correct?

I'm not an expert, but I'm pretty sure code requires you to also drive a ground rod at the barn location to ground the panel out there (in addition to the #8 ground wire you already have back to the main panel in the house). And make sure that ground and neutral stay separate in your sub-panel. The only place they should be tied together is at the main panel in the house.

As far as your sequence of events goes, that's pretty much how I hooked up the power to my pole barn also.

Jcaron is correct. You do need some form of grounding electrode at the barn panel.

And ground any metal water lines or building structural metal. Check local codes, may require more than one ground rod at least 6 feet away from primary rod.

To think of it, not sure if metal roofs, now so popular, need to be grounded.

Stan? W? Strat? Ever run across this?

Probably should be. Never ran across this.

Actually only metallic piping systems and exposed structural steel require bonding.

Of course you can bond anything you want for added safety.
Metal roofs and siding
Duct work
Tin ceilings
Etc...