One of the best Detective Conan websites I use is DCFC (detective conan fan club) -
link
It provides lots of information on the anime, manga, characters, music and pretty much everything.
Another one is Detective Conan World. It also supplies lots of info and has a rly good section that's like wikipedia which has tonnes of stuff -
link
There's also DetectiveShinichi.com -
link
It has some pretty good actual news about the anime and related stuff and it also has episode, movie and OVA guides like DCFC, so it's still worth checking out.
Hope this helps :)
