Shooting birds can be tough. They're small, fast, and they move a fucking lot. It seems as soon as you get one in the viewfinder, they take off. However, with the sun at your back and a long lens in your hand, you can grab some compelling shots without much work. I always suggest shooting when the sun is out, in a spot without too much tree cover.
The trick to a decent shot is getting close. For smaller birds, you'll need at least a 300mm lens, and you'll need to be within 20 feet to get feather detail. My favorite shots are the ones where you can almost feel the texture of the feathers. I haven't been able to do this often right out of the camera, but adding clarity and bringing out shadows in RAW editor helps a lot.
A great bird shot will have not just the bird, but a bit of the habitat, particularly contrasting colors from flowers. A unique look from the bird or a unique action, such as singing or feeding, can make a picture more interesting. I typically shoot wide open (f/5.6 on my Tamron 150-600), and aim for a shutter speed of at least 1/600 while keeping the ISO low, however a lot of photos can be saved in RAW editor even if they have a lot of noise. You may want to stop your aperture down a bit to increase sharpness, if you can afford to. Flash is a great way to get detail from birds under tree cover, but you will often need to use a flash extender on your long lens and shoot manual flash.
If you really would like to learn bird photography, check out this great link: http://www.digitalbirdphotography.com/contents.html or come shooting with Kelly and me!
