Most refuges allow individuals to erect a temporary blind. Refuge personnel will generally share information that can greatly assist you in your endeavors. Don't hesitate to ask questions. With more than 450 refuges nation wide, there's almost sure to be a refuge near you. How Know-how ranges from knowing which equipment to purchase and how to use it, to applying different techniques for different subjects.
Bird photography dictates the use of a telephoto lens.
Just how powerful, depends on the subject, and the shooting conditions. You can get much closer to a Canada goose in a city park, than in a Waterfowl Production Area. A captive bald eagle can be photographed with a 200mm lens. However, you would need a 600mm lens if you intend to photograph sandhill cranes along the Platte River in Nebraska. If photographing captive birds is your goal, this can be successfully accomplished with a lens in the 200mm to 300mm range.