I second what dalgish said. The metro area basically has three sections, Downtown (basically the area bounded by 217, the west hills, and I-5, Eastside (east of I-5) and Westside (anything west of 217 and I-5). Commuting from any one to the others is a pain. It used to take me about an hour and a half to drive from downtown to beaverton (westside), which was about 10 miles, and I'm sure that hasn't gotten much better.
If your internship is in hillsboro, I'd suggest finding a place around there. Hillsboro and west still has fairly affordable housing (which is why I'm in cornelius). Beaverton and the closer-in areas are pretty spendy, but tend to be nicer. That's not saying that Hillsboro isn't nice, there's just some older more run down sections to watch out for.