NMR sweeping magnetic field
What causes this magnetic moment?
  So does the dipole cause the proton to spin which generates the magnetic moment and if so what causes the tiny dipoles along axis? It seem to me there a rotation being caused by a rotation.


Spin is a property predicted when relativity theory is applied to electromagnetic theory, leading to the Dirac equation. It is an intrinsic property of subatomic particles, like charge. It explains magnetic phenomena such as NMR. It is a quantum property of NMR active nuclei (when measured it takes on discrete values). For spin-${\frac{1}{2}}$  nuclei, it is related by a multiplicative constant to the magnetic dipole moment of the nucleus. Thanks to spin, nuclei have an intrinsic and fixed magnetic moment in an external magnetic field. One component of this moment adopts a discrete orientation with respect to the applied field. Depending on the orientation, two states of different energy, usually called $\alpha$ and $\beta$, are possible for a spin-${\frac{1}{2}}$ nucleus.
We can define the resonance frequency in the presence of the external field using the equation you provide. For a spin-${\frac{1}{2}}$ nucleus it is proportional to the difference in energy between the $\alpha$ and $\beta$ states. It is the frequency at which the nuclear moment nutates about the applied field.


  Does the varying magnetic field vary the energy levels until resonance occurs? 


Yes. In the CW experiment, you measure the electrical signal induced by the sample in a pick-up coil while simultaneously irradiating the sample with a second orthogonal RF coil, and sweeping an applied magnetic field. The sweep alters the resonance frequency of the spins. When this frequency equals the irradiation frequency spins are excited and transition between the two states - this is resonance, the points at which the oscillating red curve (the field sweep) crosses the origin. The spins now oscillate together coherently back and forth between $\alpha$ and $\beta$ states, yielding a fluctuating magnetic field which induces an oscillating current in the pickup coil. As the field sweeps past the resonance point, the spins begin to lose energy - to relax. Relaxation causes the signal to eventually decay to the baseline. 


  Are the individual proton within the sample at different depths become out of phase with each other and the varying magnetic field is decreasing over time?


The NMR signal is an average, reflecting the behavior of a large ensemble of spins, acting coherently (nearly identically) during an experiment. The total signal is a sum over all excited spins in the sample. The applied field is as uniform across the sample as possible, so that all spins behave similarly. But in a way the spins act independently. Some oscillate faster or slower than the mean. The differences add up over time, leading to dephasing of the signal.

There is usually no spatial information in such an experiment unless special tricks are used. 


  and why dose each resonance peak have a negative voltage associated with it? How dose this negative voltage tell me about what is occurring with in the sample?


This question is not clear. The spins exist in states whose coherent oscillations induce a sinusoidal magnetic field in the RF pickup coil. The electric signal induced in the pickup coil is an AC voltage, alternating between negative and positive values until it decays completely.