ThassosIsland.de

Good site with plenty of information and supporting photos. Recommended.

ThassosTravel.com

Travel Agency site with some basic info.

Ministry of Culture

Page showing various exhibits in the Archaeological Museum of Thassos.

Vacation.net

Three pages of info and the odd photo. The latter are pretty good, but the text is basic.

OneWorld

Single page shared with the mainland city of Kavala. Sadly most of the attention is taken by Kavala.