In bitcointalk forum you could find a lot of crypto projects, at first you could look for it in google, to see about their technical team, their project, for further information, joining telegram group is a good ways to collect more and more useful news, you could read white paper and roadmap to see its current situation before investing into them
if there is any doubt as to which of them, then it is better to choose from the most ranked ones, who carry the least risk when investing. But nevertheless, in turn, I want to say that it is better to invest in the finished product, not the idea.
Yes this forum is also a good place for finding a good coin for investment and trading purposes, but there are so many other means and source through which you can also get information about good coin. I think that a lot of sites are there on interest which can give you a very good guidance about different coins.