Here are some good ways to become a self-trained Mycologist: 

If you just want to teach yourself in this absorbing and fascinating subject, then you can do it online or using various tool (such as the excellent Mushroom Project game - details below) or through using books. My advice regards book is this, have a couple of big, detailed books that require study and close reading then also have a couple of pocket style books that you can take out with you - make sure they have photos and clear descriptions. I find books with line drawings hard to use for identification.

This image will help with when some species are fruiting

The Mushroom Project Game

An ideal way to learn how to identify mushrooms. A photo and a description of a fungus are presented and the player must work out to which fungal family it belongs by using the diagram to establish answers to a very few simple questions. The player learns how to begin his identification. In the following page, he will narrow down his search further. If he has correctly identified the family to which the fungus belongs he will find its photo to compare along with others of the same family.
This game is designed to teach the student the important initial questions to ask and the features shared between members of the same fungal families. It can also be used to help identify any mushroom found in the wild.
The Mushroom Project Game A game that teaches how to identify mushrooms