>>94701i stated with a National Audubon Society field guide to mushrooms (all public libraries should have a copy or two) and just got in the habit of thoroughly identification of whatever i find and i've learned from pretty much just my own hands on experience.
how you id a mushroom is by looking at (in no particular order)
1. where you found if (i.e. what you found it growing on/the conditions of the area where you found them
2. time of year when you found it and what range your in (range is where you are geographically in the world like what state/country and climate)
3.characteristics of the mushroom itself (look at the type of gills it has, scales,shape and color, smell, and the construction of it's stock)
4. spore print (you hit the mushroom against colored paper, usually black, and see the color and shapes of the print the spores make)
and never eat anything you aren't 100% sure you've identified properly. you'll come to fined most mushrooms wont kill you of get you high nor are all the non-killing-you-guyz mushrooms vary present to eat. defiantly makes aimlessly wondering around the woods more fun by giving you something to look for.