The American Association of Colleges and Universities' Assessment page, which includes their Valid Assessment of Learning in Undergraduate Assessment (VALUE) rubrics. 

A master bibliography of web resources from Assessment Commons.

The ASSESS list-serv from the University of Kentucky.

IDEA, a non-profit in the area of higher education and assessment.

National Institute for Learning Outcomes Assessment

New England Association of Schools and Colleges' Assessment Resources.

Research and Practices in Assessment journal.

Program-based Review and Assessment, a very fine handbook from the Office of Academic Planning & Assessment at the University of Massachusetts Amherst.

And one of the best resources of all, Bloom's taxonomy, inverted with an emphasis on the higher-order skills: