Let's see.
Several Osprey/Men-at-Arms books (Aztec, Mixtec & Zapotec Armies; Border Reivers; Matchlock Musketeer; Landsknechts; Buccaneers; French Religious Wars). Along the same line Michael Wood's Conquistadors.
The five Harry Dresden books; just started Elizabeth Peters He Shall Thunder in the Sky (yeah, Amelia!).
After that, probably some more Arthurian material, to prepare for the film, including Morris' Age of Arthur.