Come rain or shine, the second annual Brooklyn Book Festival will be held this Sunday at Borough Hall (that's the attractive, outdoorsy Borough Hall; not the grotty subterranean station of the same name). Events include a poetry slam, a "define-a-thon" for all you lexicographical geeks, and readings by local and semi-local luminaries George Saunders, Joshua Ferris (Then We Came to the End, a.k.a. that book with all the Post-its on the cover) and Paul Auster.