As long as it's a rooted plant and isn't dormant give it water but don't over-water it.

You can let it get a little dry, but I would water once a week indoors. If you are planting it outside (assuming the weather isnt bad and plumerias are doing good outdoors in your area) you can plant it and leave it alone. If its cold leaves will porbably fall off, but make sure to protect it when temps drop below 35F.

Good luck and enjoy!

Thank you so much for the great advice. I am excited about my rooted plumeria. It's currently outside in a pot. We've been having warm weather here in LA (70s). I think I will buy another one today.

Buy another! They are addictive. You should be able to plant yours in the ground and not worry about them. Once established they are pretty tolerant.
Happy winter solstice!
Tally HO!