The conference hotel is the Mark Spencer, in downtown Portland, near Pioneer Square. See accommodation information.
The airport code is PDX. There is direct public transportion (locally called the “MAX”) from the airport to near the hotel, for a nominal fee. The nearest stop is Galleria/SW 10th (map). Of course taxis and rental cars are also available. More detailed arrival information.
Much more information on visiting Portland and the surrounding area, courtesy of Dave Walden.