With the upcoming release of The DaVinci Code I have been doing some research online and have found that the Wiki Online Encyclopedia is a great resource. Here is a great piece on Da Vinci..

Renaissance humanism saw no mutually exclusive polarities between the sciences and the arts, and as impressive and innovative as Leonardo's artistic work are his studies in science and engineering, recorded in notebooks comprising some 13,000 pages of notes and drawings, which fuse art and science. These notes were made and maintained through Leonardo's travels through Europe, during which he made continual observations of the world around him. He was left-handed and used mirror writing throughout his life. This is explainable by the fact that it is easier to pull a quill pen than to push it; by using mirror-writing, the left-handed writer is able to pull the pen from right to left.

His approach to science was an observational one: he tried to understand a phenomenon by describing and depicting it in utmost detail, and did not emphasize experiments or theoretical explanations. Throughout his life, he planned a grand encyclopedia based on detailed drawings of everything. Since he lacked formal education in Latin and mathematics, contemporary scholars mostly ignored Leonardo the scientist.