Beginners new to accounting should check out
Accounting Principles: A Business Perspective by
Roger H. Hermanson, Georgia State University
James D. Edwards, University of Georgia and
Michael W. Maher, University of California at Davis
One of the larger OER materials collections. The accounting section has materials covering accounting (introductory and advanced topics), taxation, auditing, financial & managerial accounting, forensic accounting, accounting information systems, accounting education, nonprofits, and more.
During the period 1987-94 Arthur Andersen funded a $5 million joint project with 525 universities to raise
awareness of ethical issues in business. This collection of mini case studies is one product of that effort.
This site lists 100+ business ethics cases, a few focused on accounting. Resources arranged in browseable list; hard to search for cases on a specific topic.