Got a hankering for more presidents? Check out these books, or see if these sites can satisfy your presidential hunger.
Great overview of George Washington and his estate.

Adams Family Papers
Massachusetts Historical Society's home of (among other things) the letters between John and Abigail Adams. Read them and imagine the months at sea these letters traveled just to find their eager recipient. Then text your significant other and get upset when they don't respond within 5 minutes.

Founders Online
An incredible archive of over 170,000 annotated documents from the Founding Fathers Papers projects. Letters, diary entries, and other works written by Washington, Adams, Jefferson, Madison, Franklin, and Hamilton.
The definitive resource on all things Thomas Jefferson and his home, and practically a of debunking fake Jefferson quotes.

Dead Presidents
Anthony Bergen’s impressive insights on all things presidential. The best part is that he often answers reader questions with thoughtful, comprehensive answers. And he’s got a pretty wicked sense of humor, too.

Presidential History Blog
Historian Feather Foster is an excellent source of knowledge for fascinating stories about the personal lives of presidents and first ladies. I just want to hang out in her attic full of presidential books and drink tea and absorb her knowledge.

Mike Purdy's Presidential History
A fantastic resource on the presidents, Mike Purdy has been writing and speaking about presidential history for years and his site is a fount of knowledge.

My Journey Through the Best Presidential Biographies 
Steve is on a journey to read all of the best presidential biographies out there, in chronological order. His reviews are great and help inform my own choices.

Highly amusing musings from a fellow presidential enthusiast. The site earns its tagline: "Scholarly. Irreverent. Star-spangled."

Presidents of the United States
Fun, fast trivia facts about each president along with some interesting bios on a nice, easy-to-navigate site.