The ONP is HUGE! Unlike many other national parks (we've been to 32) there is no way to drive through the middle of the park, as there is a mountain range there. So there is no central lodge or place from which to see the entire park.

As such, I would suggest driving around the park and staying in several different places over the course of your trip.

Day 1: Fly into SeaTac airport. Drive south to Tacoma. Spend two nights in Tacoma (I recommend the McMenamin's Elk's Lodge).

Day 2: Drive EAST and visit Mt. Rainier NP. Mt Rainier is much smaller and can be seen in a day or two. Go early, check out the peak at Sunrise at sunrise, and get in a good hike.

Day 3-4: Bid farewell to Tacoma and drive across the Tacoma Narrows bridge. Your destination: Lake Quinault. This is one of the major rainforested areas of the park, and home to some of the biggest trees, almost as large as the redwoods in California. There is a terrific drive up a river through the rainforest, and some amazing hikes. I'd recommend the Quinault Lodge.

Day 5: West to 101, then north to Kalaloch. This is a huge part of the Washington coast that is protected within the park. Pristine and natural coastlines. Here you'll find Kalaloch Lodge, which has cabins overlooking the coast from a bluff.

Day 6: Forks. Bleh. But the Hoh rainforest is here, and perhaps the best short hikes in America through a forest that seems ripped from a fantasy novel.

Day 7: North to Lake Crescent, staying in one of the main towns in the area: Sequim, Port Angeles or Port Townsend. I prefer port Townsend, and would recommend staying in the historic officer's house at Fort Flageler state park, which has a great beach into the strait, and some really interesting hikes through old WW2 era naval battlements. From here, drive up to Hurricane Ridge for spectacular views and more hiking.

Day 8: Iconic ferry ride back to Seattle (or better, Edmonds) in the morning. Then either explore Seattle a bit or head down to the airport.

There's a few other points of interest you can add in, like the Sol Duc hot springs, Port Gamble, the San Juan islands, whale watching or even the third national park in the Area, the North Cascades; they are all within reach. But this will give you a pretty thorough ONP trip.

Good luck!