We are planning a trip to Washington/Oregon May 5- May 26. Staying in Redmond, Oregon 10-17, Seattle possibly 17- 23. We would like to see as much as we can while we are out there. Any suggestions are appreciated as best things to see time wise and places to stay along the way.

Welcome to Fodor's!

Seattle is around 6 hours' drive from Redmond, and the Redwoods around 6 in the opposite direction, so hard to include in a short period without a lot of driving. Where are you coming from?

Where are you flying into Robert Field (RDM) from?
Are you visiting Bend and all it has to offer?
My advice would be to see what you want to see in the Bend Redmond area and return your rental car and take the Central Oregon Breeze bus to Portland from the Redmond airport.
The Breeze bus stops at both the PDX airport and the Amtrak station in Portland.
Take a Cascades train to Seattle or rent a car in downtown Portland. See Mt. Rainier and or Mt. St Helens and Olympic NP.
East of Portland see the Columbia gorge and the waterfalls including Multnomah.
To go see the Coast Redwoods go all the way down the Oregon Coast to Eureka CA. Come back north on US 199 to Grants Pass and take the car back on I-5 to Portland or Seattle wherever you rented it.

Thanks bunches for your help! I need more! Possible itinerary:
Tues.-fly into Seattle drive to Quinault, Washington- hike, see Ruby Beach
We'd.-drive to a scenic city along the coast-- suggestions--
See Lewis and Clark National Center
Spend the night
Thurs.drive to Another scenic place -.Yachats?
Night-
Friday.-drive to Sand Dune National Park - dune buggy?
Drive to Redwood National Forest
Stay-
Sat.-drive to Klamoth Falls on to Redmond
Spend week in Redmond and take day trip to Crater Lake.
On return to Seattle Spend a day along Colombia Gorge and Mount Hood
Night somewhere
Tour Seattle with family Monday to Sunday
Tour Ranier on Monday
Fly out of Seattle on Tuesday

Then go to Mount Ranier national Forest.

What you need to know about the Oregon Dunes Recreation Area.
http://www.fs.usda.gov/recarea/siusl...a/?recid=42465
I like hiking on the dunes in areas closed to ATVs and dune buggies.
The Redwood National Park is in northern California near the coast. Leaving the Eureka CA area, take US 199 to Grants Pass OR.
Take I-5 south to the exit for Gold Hill (Rt. 234) Take 234 east from Gold Hill to Rt. 62. Take 62 east to the south entrance of Crater Lake NP. Check now to see if you can reserve a night at the Crater Lake lodge. If not, try for a room at the Prospect hotel. You don't need to visit Klamath Falls at all IMO.
What is the attraction to Redmond vs. Bend?
Leaving Bend/Redmond take US 97 north to Madras and US 26 to Rt. 35 near Government Camp. Rt. 35 takes you down the east side of Mt. Hood to the town of Hood River. Spend a night in Hood River then see the waterfalls on the Oregon side of the Columbia River.
From Hood River you can visit Mt. Rainier or Mt. St. Helens before arriving back to Seattle.
The National Forest that borders Mt. Rainier National Park is the Gifford Pinchot National Forest.

Have you already bought your plane tickets? Do you have to do a round trip (with Seattle at the beginning and the end)? If no, I'd recommend that you fly open jaw, either into Northern California and flying out of Seattle or vice versa - that way, you can just drive in one direction, rather than losing time by driving back to Seattle to catch your flight.