>>598343There are no 100% surefire ways of telling a psychoactive mushroom from regular fungus. The ONLY way to be totally sure what you found is psychoactive is by knowing what you're looking for. No ifs, ands, or buts.
There is a lot of information on the web-- and just as much misinformation. It has been my experience that reading a book or hanging out with mycophiles is the best way of learning.
Check out
http://www.shroomery.org/. It's a site dedicated to (psychoactive) mushrooms. There's lots of info / guides about good hunting.
On a semi-related note: as a person with a general affinity for mushrooms, please be responsible about hunting / consuming. Be knowledgeable, be safe, and don't do any stupid shit to give mushroom hunters a bad name.