I'm always checking the Natural Haven out. It's one of the most coherent and sensible sources of information for hair that I have come across.
There are some things I usually watch out for:
A - Claims that hair needs nutrition and that damaged can actually be reversed. Hair is not living tissue.
B - Assumptions that natural ingredients are always better than artificial ingredients. I think this is right up there with belief in alternative medicine.
If the article/page I'm reading contain these, I know I have to take everything with a grain of salt.