Okay, back in the mists of time, there were these two holidays: Lincoln's Birthday and Washington's Birthday. For reasons not entirely clear to me, these were apparently combined into one when Martin Luther King Day became a national holiday. Since it's generically "Presidents' Day" I'm not sure if it's supposed to honor all our presidents, including say, whatshisname who died from eating cherries, or just Lincoln and Washington.
Regardless, here are a couple links to things L and W.
NIU's Lincoln Net
Abe Lincoln Presidential Library
George Washington at the White House