The guides for Around Portland are great, and really easy and fun to cycle and talk with.
Kelly was my guide for Bike Around Portland. She was awesome and super knowledgable about all things Portland. A guided bike tour is definitely the way the way to do it.
Angela guided the Columbia River Gorge Waterfalls tour, cool and also super knowledgeable about the Gorge, it's history, geology, everything. And of course Portland too. Cycling near the river on the scenic road, bombing through the trees and seeing the waterfalls and historic structures... go experience it!