The net velocity of any point on the wheel is the vector sum of the translational velocity, which has a constant direction, and the rotational velocity, which rotates with the point as the wheel rotates.

Because the magnitudes of these two velocities are equal (let's say they're both v), the net velocity for these key points is:

top of the wheel: v + v = 2v
center of the wheel: v + 0 = v
bottom of the wheel: v - v = 0

The fact that the bottom of the wheel is instantaneously at rest makes sense - if it wasn't the wheel would be slipping as it rolled. No slipping means no relative motion where the rubber meets the road.