The study of birds, as you may know is Ornithology. Here are some favorite links:
Cornell Bird Lab, "Merlin" bird identity (what's the bird?): you tube birdsong identification:
Merlin is designed to be a birding coach for bird watchers at every level. Merlin asks you the same questions that an expert birder would ask to help solve a mystery bird sighting. Notice that date and location are Merlin’s first and most important questions. It takes years of experience in the field to know what species are expected at a given location and date. Merlin shares this knowledge with you based on more than 800 million sightings submitted to
eBird from birders around the world.
Audubon Society (environment for birds, loving birds, listening to birds, identifying birds by color, size, noises, songs, calls....etc.)
www.audubon.org
I fell in love with Audubon bird calanders and stuff over 10 years ago. You can't beat the 365 pictures you will get when you get the bird calendar every year is different...
And I'm not a salesman, but anything you get from their store goes to saving and teaching birds...
Marketplace
I save the calendars. They're big, beautiful, informative, absolutely enlightening, okay, okay.. enough. Just go look!

My fave below: