McNeese State University's library has published a list of sites giving news of Hurricane Katrina for Louisiana. It includes a few sites for Mississippi. Let me just add a few Mississippi sites here:
Sun-Herald (Biloxi newspaper)
Clarion Ledger (Jackson newspaper)
Hattiesburg American (Hattiesburg newspaper)
Northeast Mississippi Daily Journal (Tupelo newspaper)
WLBT (Jackson TV station which sent its chopper to the coast and has video available)
Those wishing to assist financially may contribute to the American Red Cross or to the North American Missions Board.