ANN Claymore Page – Anime News Network’s Encyclopedia page on Claymore provides staff and cast details and other beneficial information.
Claymore Wikipedia page – Provides extensive details on the series, including manga spoilers which go beyond the anime series.
NTV Claymore site – A mostly Japanese-language site about the Claymore anime.
FUNimation Official Claymore Page – Official site for the American DVD release of the anime series. (Offers nothing more than a crude trailer at this time.)
**Note that the previously-available link to Claymore fansubs has been removed. Now that the series has been licensed for North American release, fansubs will no longer be commonly available.
Additional links will be added as I become aware of them. Please email me at email@example.com if you have suggestions for other worthwhile Claymore sites.