Read pages 1-9 and skim the rest of this really nice Introduction to NumPy and SciPy by Scott Shell. Simply skip the parts you don't understand but refer back to it as we cover more of numpy.

Watch out for an error on page 13, the result of the np.logical_or(b,c) should be

np.logical_or(b,c)
array([ True,  True,  True], dtype=bool)