Freeman's seven-volume Pulitzer Prize—winning monster of a biography is, more than fifty years after its publication, still the definitive scholarly standard. You could read it, but unless you're pursuing a Ph.D. in early American history, you probably won't want to. It does make a fantastic reference biography, though. If your school library doesn't have a copy, your local public library almost certainly does. Also exists in a one-volume abridgment by Richard Harwell.
Flexner wrote his own multivolume, Pulitzer citation— and National Book Award—winning biography of Washington in the '60s and '70s. Then he had the good sense to edit it down to four hundred pages and one volume. It is considered one of the most readable scholarly biographies. The full four-volume edition isn't so bad either.
Marshall was as close to Washington as anybody could be: he was his assistant during the Revolutionary War and part of the Federalist Party in the first years of the new republic. After Washington's death, he became the chief justice of the Supreme Court and still holds the record for longest service in that office. His five-volume biography of Washington is considered the first serious study of his life. It's an also an exercise in Federalist historical interpretation: the final volume so incensed Thomas Jefferson, the leader of the Republican Party, that he tried to keep it from being published. Many historians think it inspired Jefferson to organize his own papers so that they would have the ammunition to refute Marshall's take on American history. The biography is now in the public domain, available online through Project Gutenberg.
Ellis' best-selling biography of Washington, based primarily on a close reading of Washington's papers, is short, readable, and insightful. Although it dutifully recounts the events of Washington's life, its primary focus is on unpacking his character. As a result, its coverage of the "facts" of some of the more crucial periods—the Revolutionary War, Washington's first term in office—can feel cursory. Still, for sheer pleasure, it's hard to beat.
Washington is consistently ranked among the top three American presidents. Usually he comes in at number one. If you want to understand why, this is the book to read. McDonald leverages an entire career spent studying early-American history to explain both the simple facts of Washington's two terms in office and their significance. His deep knowledge of American history allows him to put events into multiple historical contexts, from the local and immediate to the sweeping and long-term. It's a short book, too, and very well written.
Although military history seems to be going out of style, you'd never know it from reading Fisher's book. In it, he retells the story of Washington's spectacular victories at Trenton and Princeton, in the first year of the Revolutionary War. He reconstructs the history on all sides of the conflict to recount the battles against a rich historical backdrop that helps illustrate their significance. The Pulitzer Prize winner for nonfiction in 2005, this is a colorful, learned, and entertaining book that feels shorter than its five hundred pages.
This little gem of a book was one of the first to investigate the tension between Washington, the man of flesh and blood, and Washington, the father of his country. Although it's a little old, it's still considered one of the best and most reliable one-volume treatments of Washington's life.
Maybe you grew up hearing the story of George Washington and the cherry tree. Maybe you were too smart to believe it. Either way, this is the book to blame for the tall tale of Washington and his father, and oh so many other lies "Curious Anecdotes" about America's first president. Parson Weems's largely fictional account of Washington's life was the first mythmaking biography of GW, and still the most influential. It's an infamous classic. The book is in the public domain, available online through Google Books