David Foster Wallace's books and papers and notes and doodles and all that other stuff -- it's all there for everyone to eyeball at the Harry Ransom Center at the University of Texas at Austin (my alma mater).
However, the DFW archive is open only to researchers. The rest of us have to make do with checking out the images that have been provided online -- and they've got lots of things to ponder.
Like his reading list for his lower-level college class: he had them read Carrie by Stephen King; the Lion, the Witch, and the Wardrobe, by C.S. Lewis; and Rock Star by Jackie Collins. among other works. You know this makes Jackie Collins proud on so many levels, right?
His handwritten notes are available in these books, as well as lots of papers - things like the first handwritten draft of Infinite Jest, etc. Hard to read the felt-tip pen remains, but you're welcome to give it a go.