When I try to snap views while using extrude, it just enters a value into the extrude amount, rather than snapping.
Yes, that's how it should behave. Can you describe what are you trying to accomplish? But yes, you can't snap to a view while using extrude, you have to be in the view you desire first then extrude, otherwise it will happen what you describe happened. Do you have a time stamp on the video lesson where that was done so we can clear that up?