The basic policies on tenure and promotion are on the Office of the Provost website:
Faculty Promotion

Procedures in the event of the denial of tenure or promotion are described in the Operations Manual:
http://opsmanual.uiowa.edu/human-resources/faculty-dispute-procedures#29.5

Additional resources that might be helpful for faculty include:

AAUP
The American Association of University Professors offers training and advice on promotion and tenure processes.   For questions or concerns about promotion or tenure, contact AAUP's Committee A.

College Tenure and Promotion Policies

• Education
• Law
• Liberal Arts and Sciences
• Medicine

Office of the Ombudsperson
The Ombuds Office can assist faculty with questions or concerns about promotion or tenure

Operations Manual
The University of Iowa Operations Manual describes policies related to faculty promotion and tenure.