Two good books.

A very nice introduction to cognitive neuroscience is Joseph LeDoux's book, The Synaptic Self. I particularly liked his chapters: Building the Brain, and The Mental Trilogy. The paperback edition is now under $12. Once you've read LeDoux's book Paul Glimcher's book, Decisions, Uncertainty, and the Brain: The Science of Neuroeconomics gives you a neuroscientist's view of Neuroeconomics. Both books can be read by anyone, but at the same time they don't sacrifice the science. Partly by offering a huge number of science journal references where the original science is published. Paul doesn't hold back on his criticisims of neuroscience and economics, neuroscience for leaving out cognition, and economics for leaving out the decision maker.