Can't help you a whole lot because i'm from Oregon but.... Have you taken Hunters education yet? That would be a good start if you've never hunted before. It would get you started with some good basic safety skills.
Then.... talk to Fish and Game, Talk to the Washington equivilant of the Oregon Hunters Association.
Oregon has some good programs and maybe Washington will have something also.
As the allure of hunting big whitetails becomes more and more a passion for many, we are finding that the recent (historically speaking) popularity of hunting deer from a tree stand is becoming the way to do it. I'll make no statement either for or against that technique here. This will be simply an essay on what I feel are some outstanding rifles for tree stand use.
Before we go even one more step, let's all remember that safety is first and foremost for anyone wanting to hunt...