The information on this site comes from a variety of sources. Wikipedia, as ever, helped a great deal with some of the basic biographical details of individuals. The biographies section of the excellent Scienceworld also helped flesh out some of the stories a great deal. This excellent biography of Alan Turing goes in to far more detail than I could hope to, and this site does the same for Leonhard Euler. Other sources were picked from around the web, but I am ashamed to say I don't appear to have written them all down. One invaluable resource, especially with respect to Bernhard Riemann and Ramanujan, is Marcus du Sautoy's excellent book The Music of the Primes. If your interest in mathematics has been piqued by what you've seen on this site, then I suggest you buy this book immediately. It's wonderful.
If you liked the section on Euler's Identity, then you'd probably like this video which goes a little deeper in to the mathematics whilst still being concise and amusing. It also inspired me to think about communicating mathematics in a slightly different way than usual.
This project was done as part of an MSc in Science Communication at Imperial College London. Please see the about page for more information.
Finally, if you want to donate a little bit of your computer's processing power to try and find new prime numbers, then please visit the GIMPs project site.