Biographies of Scientists
Asimov, Isaac
Edison, Thomas
Einstein, Albert
Faraday, Michael
Hogben, Lancelot
Jenner, Edward
Leonardo (da Vinci)
Newton, Sir Isaac
Sinclair, Clive
Sykes, Kathy on TV Lives
If you can't find the scientist you are looking for, you could try some of the extensive resources listed in h2cm