This video (10:12) shares quick tips on using the Iowa legislative site and (starting at 2:20) searching with the Legislative Document Research Page.
A basic understanding of the legislative process and legislative terminology in Iowa will make your research more effective.
The Iowa Official Register includes information about all three branches of Iowa government, including listings of government officials. It also includes other information about Iowa, as well as some listings for federal and local government.
In 1890 early lawmakers organized a permanent society known as "The Pioneer Lawmakers' Association of Iowa." The purpose of the organization is to preserve the history of Iowa and a biography of its public men and women. (Description taken from Iowa General Assembly.)