Boswell's London Journal. James Boswell kept a series of journals throughout his life, and the earlier ones are especially interesting. Boswell's London Journal, 1762-63, edited by Frederick A. Pottle, is commonly found in public libraries and used book stores -- in fact every used bookstore I've ever been in has had at LEAST one copy.
Boswell was in London to secure an officer's commission in a Guards regiment, and his journal makes several mentions of military matters and activities. More importantly, Boswell is fascinated with the life of the common people, and virtually every page contains mention of some item of clothing, food, drink, or local culture (NOTE: The young Boswell is a rather seedy character and tends to brag quite a bit about his various "conquests". If you are easily offended by accounts of promiscuity steer clear of Boswell)!
Dictionary of the Vulgar Tongue. This 18th-century dictionary was originally written by Captain Francis Grose and published in 1785. Though it post-dates our period ever so slightly, it still offers an insightful glimpse of common language usage of the late 18th-century. This is not simply a book of period "dirty" words. It is a true dictionary of period slang terms, colloquialisms and phrases in common usage and contains nearly 4,000 entries!
This handy book makes an excellent reference tool. Even if you never intend to attempt a first-person impression, Dictionary of the Vulgar Tongue offers many ideas for adding a period feel to your camp and ropeline conversation. You can find reprints of the third edition at used book stores, or try Don Hagist.
At the Crossroads. This is the story of Michilimackinac during the American Revolution. It is packed with illustrations and does a good job of describing the people and events here in the Northwest that influenced the outcome of the War. This one can be had through Smoke and Fire (1-800-766-5334) and possibly some of the other regular NWTA sutlers as well.
The Old Northwest in the American Revolution. This book is a collection of essays edited by David Curtis Skaggs and published by the State Historical Society of Wisconsin. The essays deal with local personalities, military expeditions and territorial disputes, as well as political events and policies that affected the Northwest Territories.
Even if your impression is of an eastern unit, because of where we re-enact, we should all become familiar with the events of the Revolution that happened in our own backyards, and this book is an excellent source for information specific to the Northwest Territory. If you can't find it at your local public library, check your school or university library -- or find it through inter-library loan.
Journals, Diaries and Memoirs. A variety of these have been published over the years. Of special interest are the journals of British, German, and American officers who served during the war.
Your best bet for finding these is to visit historical society libraries. A few of the better ones are still in print and offered through several sources -- check the June and July issues of The Courier for some excellent primary-source selections offered by both Don Hagist and the Henry Knox Bookstore.
Other Titles Worthy of a Look:
The Revolution Remembered; Dann
Paule Revere's Ride; Fischer
The Fire of Liberty; Wright
Private Yankee Doodle; J. P. Martin
Redcoats and Rebels; Hibbert
Less Than Glory; Gelb
Standards and Colors of the American Revolution; Richardson
Encyclopedia of the American Revolution; Boatner