Double Helix: 50 years of DNA

DNA from the Beginning

This site has modules that cover the history, explain the code, how DNA can be manipulated, and the applications of this knowledge, among other things.

DNA Structure

Very short animated video explaining the structure of the DNA molecule.

How DNA Works

Explaination of the structure and function of DNA.

Linus Pauling Online

This is the discovery of of the structure of DNA from Pauling's perspective.  The site has a searchable database of Paulings research notes.

Linus Pauling and the Race for DNA: a documentary history

A collection of  primary documents concerning the details of the pursuit of DNA.