All good bits of advice, except for the directions to the coast.
The coast is about two hours away from Portland. West, not north. There is no Route 1 to the coast. To get to Cannon Beach, go west on US 26. Cannon Beach is yuppie beach heaven. Beautiful beach, though, and good, walkable planning. Good design standards. We use some of their approaches as model here. Seasie is a little north of Cannon Baech, and is popular, but I went there for the first time a few weeks ago and was disappointed. It seems a little like an east coast shore town, not really like Oregon. YMMV.
To get to my own Lincoln City, take Route 99W west then pick up Route 18. 18 ends at US 101, which takes you into Lincoln City. Its a blue collar type resort town, 7 miles of beaches. Our Taft district Urban Renewal project is the talk of the coast, if not the state. If you (or any others of the respected Cyburbians)have any interest in coming to Lincoln City, let me know. I'll have company while you are in the area, but I will make arrangements for you if I can.
Powells' is a must-do when in Portland.
MAX light-rail and trolleys. The no-fare zone (Ride buses and lightrail for free downtown)
Hawthorne District on the east side is my favorite. Stores and food. Walkable, great mix of people (goths and yuppies and oldtimers)
Nob Hill neighborhood, aka NW21st Avenue, is cool. Also trendoid, but lots of good restaurants and shops. Wildwood restaurant, 1221 NW 21st, is true NW cuisine and great. I am having dinner there on Sept 23rd with my parents (my father's 80th bday).
If you can go up the Columbia into the Gorge, do it. Recommedned route for a short daytrip is to go east on Interstate 84 (required stop at Multnomah Falls), to Hood River (wind surfing central), then south on rte 36 into the mountains to US 26. East on 26 to Government Camp. Required sidetrip to Timberline Lodge (seen in The Shining), a fantastic WPA project and probably the best of NW lodge architecture. 26 will take you back into Portland. Watch for the UGB near Sandy.
Chinese Garden downtown. In the area of the Saturday Market (under the bridge market someone mentioned).
Oregon Museum of Science and Indusrty and the Zoo are tourist staples
Orenco Station development - mixed use, transit oriented.
www.orencostation.com/
The Willamette (wi-LAM-it) waterfront (Tom McCall Waterfront Park, named for St. Thomas McCall, the governor who started the LU system in Oregon and told Californians to bring their money, leave it here, and then go home)
Park Blocks is a good idea. Includes the Portland Art Museum as well as PSU.
Further north is the Brewery Blocks, which unfortunately is not a bunch of microbreweries, but the site of the Weinhard brewery which is being redeveloped into mixed use. Not sure how far along they are, might be just at the tearing down stage.
To see where big boxes go to die, visit the Jantzen Beach supercenter far north of downtown beside the Columbia River. Seems like dozens of big box stores all side-by-side.
By the way, it's tres chic to call Portland "PDX." Stumptown is OK for locals.
In Central Oregon Bend is a nice place to go, but highly developed. About 20 miles west of Bend is Sisters, a very small town with strong design standards (the wild west look) that work. We always stop in Sisters to eat when we are going further east (and we ofter go just to the Sisters area, where there is great cvamping fishing, etc.) Check around first about going to the east side of the Cascades, though, because there have been some road closures due to fires lately (BIG fire burning about 20 miles NW of Sisters)