
When I'm thinking about birds to draw (assuming I haven't just seen them on a walk), I start by thumbing through a couple of coffee-table sized photo reference books, both published by Dorling Kindersley.
Once I've found my bird, I turn to "the Internets" to see if I can find other photos and/or videos of said bird so I can see other angles, other plumage, how they move, etc.:
The internet is a good and lovely thing for this purpose.
And then I doodle. I struggle, but it's fun and I feel like I'm getting to know something a little bit better.