A search for "Phineas Gage" on Google Books returns 756 results. Most are books and journals on neuroscience, psychology, and brain injury that include a mention of Gage, or at most a chapter about him, but there are two books about Gage that we have read and recommend.
A Selection of Internet Links
Type "Phineas Gage" into the Google search box and as many as 70,000 to 80,000 results will be found. There is no need for us to supply a long list since you can search for yourself. What we present here are a few of the sites that we found especially helpful when we began our search. We will add additional links from time to time.
Wikipedia page on Phineas Gage: A good starting point for information with notes and links
Deakin University Phineas Gage Information site: A multi-page site maintained by Malcolm Macmillan, now of the School of Behavioural Sciences, University of Melbourne, Victoria, Australia
Warren Anatomical Museum, Countway Library of Medicine, Harvard Medical School exhibits the Phineas Gage's life mask, skull and tamping iron, along with many other fascinating medical objects.
BBC Radio 4 Case Study on Phineas Gage was broadcast in May 2008. This linked site has an audio of the full program. It was our introduction to the delightful song about Gage by Banjo Dan.
Phineas P. Gage, The Person is a multi-page web site with information and photographs about Cavendish, the accident site, and the routine of railroad work at the time.
An amazing video, The Tale of Phineas Gage, Digitally Remastered, by Ratiu and Talos shows the passage of the tamping iron though the skull of Gage.
If you are not familiar with the daguerreotype process check out the web site of the the Daguerreian Society.