The trouble with finding someone who gathers them locally, is that there are very few people these days who do. For instance, I am the person people come to to find out about the plants so where do I go if I don't know something?
Good thought about the places to take them though. I think the place around here might be the most local Wildlife trust branch. I'll give it a go.
The books I have don't just rely on illustration for identification, they go into all the things like the way the gills are attached, the colour and layout of a spore print, the time and place they may be found growing and often, what they might be confused with. Having said that, you are right...the best way is to be shown by someone who knows. It was passed down from one generation to the next once but it's mostly been lost in the last couple of generations.