At Guy Derdall's
Battleships Carriers And All Ather Warships a lot of Information could be found:
USS Iowa
The Department of the Navy has a huge Picture Collection at their
Naval Historical Center and is making a growing part of it available online:
Online Library of selected Images: USS Iowa
Ships of the spanish-american war:USS Iowa
At a Site about
The Spanish American War Centennial Website a good history of Iowa's involvement in the 1898 war:
USS Iowa