It's been 10 years since I visited Portland, Oregon. The most memorable part of my visit was going to the Monet exhibit at the Portland Museum of Art, which obviously has long since moved on, but it is a nice facility.
You need to check out the Bagdad Theater & Pub, if for no other reason than the outside shot has been in several movies and is bound to be again.
The only other restaurant I remember is Hamburger Mary's, but I just checked their website and that location has closed.
Portland is a beautiful city, make sure to check out the the southeast/Hawthorne Neighborhood. That's the uber liberal, hippie and hipster part of town. If I remember the northeast part of the city is where all the big old money houses are, beautiful neighborhood to walk. When I visited, it was in November and the rainy season was in full swing, it was anywhere between a mist to a drizzle to downpour the whole week I was there. I didn't mind because I was visiting my boyfriend at the time and a travel agent friend had given me a free ticket. Good luck and have fun in your travels.