McMinnville is easiest by car. Oregon Route 99W runs through town, and Route 18 links it with the coast and the Portland side of the valley. Portland International Airport is the nearest major airport; from there the drive usually takes a little over an hour when traffic behaves.
Yamhill County Transit buses connect McMinnville with Newberg, Tigard, Hillsboro, Salem, Sheridan, and Grand Ronde. They are useful if you are patient, but a car gives you far better access to wineries and rural sights.