If you just bought it now and don't plan on hunting until this fall, there's no need to wash it right away. Put it in an airtight container until hunting season, then you can either wash and dry it before going hunting, or simply regenerate it in the dryer and be on your way. Like nodog said, each time you wash the garment you shorten the lifespan. Only wash when 100% necessary, and regenerate it in the dryer as much as possible - or as much as you want. And be sure to store it in an airtight container when you're not wearing it in the field. The suit will act like a sponge and adsorb odors from outside as well as inside.

Also, be sure to spray your hands, head, and neck area in scent kiler before going out in the woods. This will cut down on scent you leave behind while going to/from your stand. And ALWAYS be sure to wear a Scent-Lok headcover of some sort. The majority of scent emmitted from the human body comes from your head/face.

Don't forget to sing "Be The Dominant Predator......" in your head as you stroll happily to your treestand.