Reading Jeff's book is a great intro. Then you can read some intro books like one of C. Koch's - very accessible. Brain theory is actually pretty readable until

Reading Jeff's book is a great intro. Then you can read some intro books like one of C. Koch's - very accessible. Brain theory is actually pretty readable until you get down to the biochemistry of a neuron, which is wildly complex. But, they still don't know how it all works, so it is fairly incomplete to read about (unlike much of physics, chemistry, or even many areas of biology)