Also useful, if not necessarily 5th ed specific: Seattle 2072, Seattle Sourcebook, Sixth World Almanac, NAN (Native American Nations) Volumes 1 and 2, Sprawl Sites, Bug City, London Sourcebook, Germany Sourcebook, California Free State, Tir Na Nog, Tir Tairngire, the Target: series, Aztlan, New Seattle, Denver, Year of the Comet, Shadows of: series, Corporate download, Corporate Enclaves and Feral Cities. These are the setting sourcebooks, from 1st ed on. Not necessarily in any order.
Edit: definitely not a high priority for learning the system, but good for the background/setting info.