Guide to the stuff on this map: The red line marks the 4.8-mile driving loop, while the yellow and orange lines mark the three hiking loops. From left to right, they're the Meadowlark Trail (1.5 miles/2.4 km), the Kestrel Trail (0.5 miles/0.8 km), and the Bittern Marsh Trail (0.5 miles/0.8 km).
The pale green bubbles show the locations of the refuge's two viewing platforms. The northwest viewing platform is at the refuge's visitor center. Wetlands to the right of this platform are typically occupied by ducks in the winter, and I've seen some skittish, hard-to-find birds near the platform, including a Virginia Rail. The area around the southeast platform is probably the best place for photographing the sunset, as the (usually) still waters reflect the light nicely and are usually dotted with assorted waterfowl. The immense flocks of geese tend to wander around the refuge but are sometimes here at sunset as well, and it's awesome to behold 10,000 or so of them taking off and wheeling overhead as they head for their nightly roosts.
The hiking trails go through timber rather than wetlands, for the most part, and have lower bird populations overall but are where you're more likely to find hawks and owls. The Meadowlark Trail (the yellow loop at top left) passes by wetlands as well as trees, but the birds seem more skittish of hikers than cars, and you'll usually be able to get closer views of waterfowl on the driving route.
The orange bubble marks the location of a photo blind that can accommodate two people. It faces west, so by mid-afternoon on sunny days most of the birds you're spying on there will appear as silhouettes.