given a fair amount of neurobiological and mathematical background id recommend the book "spikes" by bialek, rieke and warland. imo its vital to keep basic concepts like simple arithmetic and logic operations with neurons, hodgin-huxley, p/d/d2 type resonses, shunting inhibition, leaky integration, the time constant regarding integrator neurons and coincidence detector neurons, convolutions, correlations, filters, lateral inhibition, center/surround antagonism, ltp and hebbian learning in general and all such things in mind in order to get to a clear understanding, but that also depends on what you're interested in.