If I think of other things I'll add later.
First, the Best Western up North I'm assuming is the Inn at the Meadows. Not where I would choose to necessarily stay but affordable and has decent ratings. Also, if that's where you're staying you're only one exit north of a Tri-Met Park and Ride. Tri-Met is our public transportation system. It's not NYC or DC subways but it's pretty decent for a city our size. I'm sure you're going to have a car but my recommendation is to use the train when you can. http://www.trimet.org If you parked for free at the park and ride it would only cost you $5 each for an all-day fare. Then you don't have to worry about finding parking and PDX is a very walkable city.
You have to go see Pioneer Courthouse Square. Lots of events take place there throughout the year. Also I high'y recommend walking the South Park blocks. Nice area around Portland State. Again, accessible by Tri-Met easily. Also walk Riverfront Park downtown (easy walking from Pioneer Square to Riverfront Park)
As for sports. We do have the Trailblazers for BB, the Timbers for soccer, and the LumberJax for Lacrosse. I think all of those play at the Rose Garden Arena - again easily accessible by Tri-Met. For personal activity it's a great biking/hiking place and so are the surrounding parks and mountains. Kayaking is done year-round here.
Food and brewpubs. You'll find brewpubs all over. I like the Lucky Lab because you can take your dog. McMenamins, Bridgeport, Rogue, Widmer are all good.
I'm a little older now so I don't get out as much but I believe the hopping place on weekends (and other nights) is still the Pearl District. http://explorethepearl.com and http://www.urbanspoon.com/n/24/2320/Portland/Pearl-District-restaurants. I don't see anything on the list I've heard bad stuff about. Oba and Paragon I can vouch for and they have good happy hours. Byways Cafe is great for breakfast but expect to wait a long time. Mother's downtown is also great but it's more of a splurge than someplace to go all the time.
I'm too old to speak to the bars where your son might want to hang out. Been out of that scene for a while. So hopefully someone else will fill in on that.
If you have time you should go to the coast. It's beautiful.
On Edit: You have to go to Voodoo Donuts. They make the most unusual donuts. Again, expect a line most of the time.