Painting hard finish plaster.

Oh boy!, what a nightmare.
Could not believe the varying to do's and not to do's I have just experienced in the last 24 hours.
Mission is to paint a couple of rooms with freshly plastered walls (hard plaster).
How would you paint?, and what would you use?.

Given the similarities to drywall mud I'd wait until it's thoroughly dry, maybe test with a moisture meter and then prime it well with two coats of a good quality universal primer and then use water based interior paint on it.