Morning sun / afternoon shade is the best thing. Or, anywhere where it can receive bright white indirect sunlight all day would even be fine, so that the plant won't scorch or dehydrate too quickly.

If you aren't comfortable putting it in the ground, invest in a nice container for it. Hydrangeas grow great in them. You can overwinter it in a cold place where the roots won't freeze, such as on a porch, in a garage, against a foundation under a deck, or in a shallow ditch filled with mulch or leaves.

I too, am going to get a hydrangea from my neice. she ordered it on-line and I am not sure of the delivery date. It is called Endless Summer hydrangea. I am still trying to find out the best spot for it. I would like to plant it in the backyard so I can see it from my deck. Does it need morning sun or afternoon sun?Can I plant it in a pot? if so what size pot? I lie in zone 7, jackson, Tn.

Be aware that many of the gift hydrangeas they sell at the grocery are dwarf varieties, and will never grow larger than about 2 feet or so. I learned that the hard way! At least hydrangeas transplant well so you can move it later if you need to.

aadepa, was the hydrangea blooming when you got it? Mother's Day gift perhaps? If so, unfortunately, the hydrangeas that are offered for Easter or Mother's Day and already have huge blooms, have been forced to bloom early, and the plants are all exhausted and tend to have a hard time adapting to 'normal' growing conditions, so if it dies, don't blame yourself.
Christine