I realy dont think there are any good restaurants serving authentic Indian food in Amsterdam. I had tried all the restaurants when I first arrived here and I must say, it made me crave real Indian food even more!!!
Having said that, Mother India and also Memories of India (over the top on oil & spice) do a passable imitation. Kohinoor comes next.
We dont have any seperate website for Indians so far.
But this is a quite useful one for your activities or to post your queries.
You can expect the answers (sometimes funny and thought provoking answers from GANI9999!!!!!)