Below is a list of popular metal detecting related magazines that are great for those rainy days. They include tips, how to articles, and lots of interesting stories of metal detecting finds.
American Digger Magazine
https://www.americandigger.com/
Relic Hunter Magazine
https://www.relic-hunting.com/
The Coinhunter Magazine:
https://www.thecoinhunter.com/
Treasure Hunting Magazine:
https://www.treasurehunting.co.uk/
Western & Eastern Treasures: Published since 1966.
The Searcher: UK based metal detecting magazine