We have plenty of sun where I live for drying fruit etc. but mushroon season is colder and a little bit moist.
So I tried a few ways of drying them but the 2 most effective were layered in a tomato box between newspaper and put in the airing cupboard or simply threading them on a string and hanging them in the living room near the fire (or whatever heat source you all have). Put some sort of covering on them (you guessed it - newspaper worked well for me) to keep the dust off.
I've just finished sun drying my first tomatoes but lost one batch due to my very greedy dog

Who ever said dogs are carnivores.
BTW I have a great book called "Food From Your Garden" It's about 20 years old (at least) but it has become my bible. Everything from growing to preserving to brewing. There's a great section on salting veg (caution to those on a low sodium diet) and even a section on bee keeping.