The big thing is to find forums where the mods are not pushing any specific product or company. This board was my first board ever in this new world I entered a few years ago now. The advice was backed by science (shocking!!!), and the mods do not run logs or recommend specific brands of products. Yes, they say "use Prami" or "use Deca", but they do not say "use RUI Prami" or "use PSL Deca". That would compromise their integrity. If members start complaining about a sponsor, and investigation shows the sponsor has gone from being a good company to a bad one, this forum will boot the sponsor. It is one of the things I like about this forum.
Still, you have to read all reviews with some skepticism. I got blasted a bit ago for not making it clearer that I have a tight association with PSL - so I clarified that in the line under my name (since only sponsors have signature lines here). It was right to do so, and I am glad it was done, so others can be more skeptical about what I write wrt PSL and my integrity could be verified as still top notch, that I was not trying to "get away with anything". My personal integrity is such that I would never write something that was not true, and I would go even as far to write negative things about any product I felt deserved it - even if I received the product for free. My online integrity is my only real online currency and I want it to stay valuable. But none of you out there in anonymous Internet land can know this for certain, so little statements like that under my name are needed and I feel are a good thing.
So yeah, be wary, read many reviews from many sites, but try to keep your eyes open for sites where the mods push specific brands of products or specific companies. That should be a huge red flag that that money is coloring judgement. If a specific brand or company is good, they do not need mods to push hard for them, there will be a lot of forum members doing it already.