Nothing replaces a good mentor when you are learning about mushrooming. We have been lucky that Josh has a few friends with more experience that have mentored us. Also in our area, there are local mushrooming events pretty close by.
You can get sucked into an infinite Google search with tons of online resources. But we have found that while Google is great, a lot of times where the mushrooms are, there is no internet service. And part of the experience of mushrooming is cherishing the silence of the cathedral like woods and the freedom from our ultra-connected society. So while the internet can be an invaluable resource, here are some books we have collected over the years that have been really helpful, from beginner on up. We toss these in the car when we are headed out so we have them on hand if we come across a new specimen.
This book is sitting in my amazon cart for me to buy later. We still have so much to learn!
I am sure there are tons of other wonderful resources. These are the ones we currently use and find to be really helpful. Ultimately, there is no replacement for common sense and care.