You've got to admire him. The former President writes decently about everything from hunting and fishing to Mideast politics. Heck, even his poetry is good. (Okay, I may get some argument there.) And ''Nest'' -- the first novel published by a President -- is a pleasant surprise. Yes, it's a little formulaic. Yes, there's some speechifying. But Carter's really done his homework. Occasionally the book feels a little too much like a history lesson, but for the most part, this bloody era is brought to life. The main character, Georgia farmer-turned-patriot Ethan Pratt, leaps off the page, as do a host of minor characters, and subplots are woven together as deftly as the fabric on the loom of Pratt's wife, Epsey.