With the spark plugs out, crank the engine until you see oil pressure. It'll crank pretty fast and build pressure after a couple tries.
Also don't prefill the oil filter, if the oil pump wasn't preprimed it'll take very long for the air to overcome the oil stuck in the filer. If you're not sure, just crank it with no oil filter until you see it spit out oil, then the pump is primed. Put back the filter and crank for pressure.
I'd crank until the oil light goes out, let it rest while I button up the some things, come back and test crank again to confirm the oil light instantly goes out. Then you're sure everything ready to fire up.