You can read full details about how to get in on this fabulous fan opportunity here on the Little Shop blog, but in summary: The reading/signing is ticketed, and although the tickets are free, you have to pick them up either A) from Little Shop of Stories today, i.e., Monday, November 30th, before 8:00 pm, or B) via telephone or at Little Shop starting on Monday, December 7th, and ending whenever they run out of tickets.
Knowing Neil Gaiman fans (we're not all exactly rabid, but oh crap is this a picture of me dressed up as one of his characters? Hell, nevermind, we're all crazy), tickets will probably run out. For general reference, I went during lunch today to pick up mine, and received ticket number 318 of X, where X is a number which hopefully my query to the store will produce.
Gaiman has a