Ken, I've had teachers who lectured without notes, only one who assigned no readings.
The exception was a crazed mathematician -- Alex Abian, a very bright man -- who taught the diff eq for engineers and other idiots course. He didn't teach from the standard text, instead developed on the fly a course on the algebra of the differential operator that led naturally to solving differential equations. He did, though, hand out problem sets.
For most subjects a college-level course with no readings is inconceivable.