Unfortunately there are not many sites about Astrud on the Internet but there are a few, here are they and also links to other good jazz sites.

Astrud Gilberto - A site from Gregmar studios
Astrud Gilberto 1960's Fan Page
All Music guide information about Astrud Gilberto

Other Jazz sites
Jazz online - A cool site containing info about many great jazz musicians
One Stop Jazz on the Web - an organized index of jazz resources on the internet.
Stan Getz
Nina Simone
Billie Holiday
Ella Fitzgerald
Miles Davis