Now is the time to plant peonies! Put compost and some bone meal into the hole you are planting it in. Be sure not to plant the eyes deeper than 2" below the ground (I use a ruler). Water well.

The foliage on the peony varieties I have stay very nice during the summer and fall. Last year was the first year I had mildew and cut the stems back in late summer to just above ground level.

Your peony should be planted in full sun. I'm not good at the spacing issue...so I'll leave that to someone else to address.

What cultivar did you get?? Enjoy!
Judye

Ditto for what Judye says....the 2" depth is a must.
Three feet apart is the usual spacing between other peonies and other plants.

Do prepare for their emerging in the spring by providing them with some form of support....stakes (don't skewer the roots) or a wire cone and let the plant grow up into the support. Otherwise the large weight of the bloom will certainly bring them down.