I’m originally from the Pac NW, but live in Belgium now. There are a lot of things to do in the Seattle/Portland area but I am listing things unique to the area and things I don’t think you will find in the UK.

Seattle:

Things to do:
1. Definitely go to the famous Pike Street Market and the fish market there. http://www.pikeplacemarket.org/
2. A fun tour is the underground tour (and I am not talking about the subway). http://www.undergroundtour.com/
3. Snowqualmie falls is about 1-hr drive from Seattle and well worth it. http://www.snoqualmiefalls.com/
4. If you get the chance and it is nice out, go for a sale out on the bay.
5. Of course, the Space Needle http://spaceneedle.com/


If you are interested in seeing some amazing forests and wild beaches, I’d suggest a day drive to the Hoh rainforest. http://en.wikipedia.org/wiki/Hoh_Rainforest Some of the tees in this forest are aprox. 95m high. It is a really cool place and there is

Portland:
1. NW 23rd Ave. – this street has lots of eclectic shops, tons of coffee shops, restaurants, etc. It is a good place to walk up and wander. It is not big, more like a neighborhood while being blocks from downtown.
2. The Pearl Dist. – this can be interesting if there is something going on. There are a lot of art shops and there is a thing called “First Thursday” where the First Thursday of every month, all the local artists and stores stay open late and there is art being showcased
3. Timberline Lodge – Up on Mt. Hood, this is an easy drive from Portland, about 1-hr. I’d suggest going up there for lunch. You can hike up there, and yes there will still be snow capped top due to the glacier. It should be really beautiful. http://timberlinelodge8-px.trvlclick.com/visit/
4. Multnomah Falls – This place is really cool. It is 189 m tall. The lodge has great food. http://en.wikipedia.org/wiki/Multnomah_Falls
5. Cannon Beach – From Portland, 1-hr drive to the west, you will be at the Pacific Ocean. Cannon Beach has a lot to do. It is a nice mix of a big beach, restaurants, galleries, shops, etc. http://www.cannonbeach.org/


As for lodging in Portland, most all of downtown Portland is connected very well using the Max (the light-rail system). You can ride for free in downtown. It might be worth your money to stay at a place like that Governor Hotel that is 1-block from the MAX so you can easily hop on and off.

In Seattle there are several hotels located close to the airport that link easy to downtown Seattle. I’d suggest the Hilton Seattle Airport & Conference Center. I have had great service here and found it easy to get to downtown.

Not sure if this is what you were after, but I hope one or two items helps you plan your trip.