This guide provides links to free websites related to science and technology. The lists have been compiled by Professor Aditi Bandyopadhyay; annotated by Aditi Bandyopadhyay and Cathy Fester; updated by Aditi Bandyopadhyay and Janet Wagner. If you would like to suggest a website to be included in this guide, please email to Professor Aditi Bandyopadhyay bandyopa@adelphi.edu