What I'm recommending, I have not done myself...so take it with 3 grains of salt.
Katanai Rock looks really cool! Here's some photos from Mazamas:
http://www.flickr.com/photos/aymadventures/sets/72157618298885006/
Mystery Trail looks like great fun as well...lemme look up some beta (or google it yourself). Eg. Kevin's got some nice shots from it to give you an idea ("MT" labeled ones):
http://www.flickr.com/photos/28170238@N06/sets/72157606066304281/
also:
http://www.flickr.com/photos/28170238@N06/sets/72157617892773583/
Think both of these will require a rope at least for rappels (from the photos I've seen).
I second what OJ & Brian say above about the book (the new Gorge CLassic Climbs). You can also buy online from Tim's website, here:
http://www.portlandrockclimbs.com/portland-rock-climbs
(not all things in there are technical). sorry - same as Brian's link.