The first consideration when placing your coop in your yard is to pick a spot that drains well – you do not want to place your coop in a low spot in your yard. Standing water in your coop can make for a stinky coop. High ground is dry ground! The second consideration is to position it in a place that makes it most convenient to water and feed your chickens. Pick a spot near a hose bib so you aren’t having to drag a hose across your yard to water your chickens. A reasonably sunny spot is also good as it will help dry up your coop.
Here is a great blog article on this topic: Where to Build Your Chicken Coop