At first glance, a butterfly's wings look totally symmetrical. The designs on one wing seems to mirror the designs on the other side, yet upon a closer examination of the butterfly, it becomes evident that even though they may be similar, that in fact they are asymmetrical. That is the same way with the human brain. The sides look like they are the same, and yet they are not. Each hemisphere of the brain is mapped out a little different than the other. In his book "Hemispheric Asymmetry" Joseph Hellige convincingly outlines and explains about the Asymmetry of the brain. He is very careful to repeatedly point out that even though we have hemispheres of our brain, they still function together as a whole. Rightfully so, he encourages us to look at the whole brain and to consider how it works, much like a multi-part computer. His book is not light reading, but it is very informative even for being over 17 years old. Some would find the subject of neuroscience quite heavy to read about, but Hellige's writings are peppered with a bit of dry humor that tickled my funny bone at times. If you find the subject of brain function interesting, I would suggest this book as a place to start.
Robert Ornstein gives us a Psychologists view of the hemispheres of the brain and our mind in his book entitled "The Right Mind". Even though it was written over 13 years ago it still holds a great deal of good information and gives us a much deeper understanding of the origin of sided-ness in our world. The book is written in such a way as to make you feel like Ornstein is actually having a conversion with you, rather than talking at you. Since it is written in this manner, then it seems to flow and before you know it, you have worked your way through large bits of it. I feel that Ornstein's writings are a good compliment to Hellige's studies, so I would recommend that the two be studied sequentially.
If you want to follow another road to brain function, than you might want to read Howard Gardner's book entitled, "Multiple Intelligences; The Theory in Practice" which gives us a whole different road map of what the brain (or intelligence) is like. He relies not on what "sided" the brain is, but what classification of intelligence we fall within. His theories have been embraced by educators around the world. His book "Frames of the Mind" sparked the imagination of an audience that he hadn't even thought about writing for, as his efforts were aimed at colleagues. Instead and much to his surprise the spark ignited a Multiple Intelligence movement that is alive and well to this date.
Other authors have taken on his theory and have written their own views of Mutliple Intelligence. One such author is Dr. Thomas Armstrong who has taken the subject and ran with it. He has authored multiple books on the subject, one of which addresses children that are labeled as ADD. He contends that the ADD child is mislabeled as having a "learning disability" when in fact they are using one of the many "intelligence" that aren't readily addressed in public education.
Interestingly enough co-authors Jeffery Freed, M.A.T & Laurie Parsons attack the same subject of ADD from a right-brained, left-brained approach. In their book, "Right-Brained Children in a Left-Brained World" the co-authors show that "right-brained" teaching methods can be employed to address the learning needs of these mislabeled children. In doing so the children make leaps and bounds towards learning the same skills that other so called "normal" children learn in school.
Two different (either Armstrong's views of intelligence and learning or Freed and Parson's Right-Brained teaching) approaches or ways of thinking still point to the same type of conclusion, not everyone learns the same and teaching methods need to be altered and tailored to the learner.
In the same fashion, whether you look at Hellige's views of the make up of the hemispheres of the brain or Gardener's view of intelligence one common conclusion can be found, our brain, mind and personalities are very complex indeed.
