AACU's Portfolio Assessment page with links and examples.
http://www.aacu-edu.org/issues/assessment/portfolio.cfm

Abrenica, Y.  Electronic Portfolios.  Defines the meaning and use of electronic portfolios, answers questions as to the benefits and practicality of their use, guides beginners in creating an electronic portfolios by using a step by step instructions and identifies the equipment or technologies needed to accomplish such portfolios.
http://edweb.sdsu.edu/courses/edtec596r/students/Abrenica/Abrenica.html

Alverno College's digital portfolio
http://www.alverno.edu/academics/ddp.html

Barrett, H. Using Technology to Support
Alternative Assessment and Electronic Portfolios
http://electronicportfolios.com/portfolios.html

Barrett, H.  Dr. Helen Barrett of the University of Alaska offers her favorite links on
Alternative Assessment & Electronic Portfolios.  This is a massive list.
http://electronicportfolios.org/portfolios/bookmarks.html

Department of Education Office of Research (1993).  Student Portfolios: Classroom Uses
http://www.ed.gov/pubs/OR/ConsumerGuides/classuse.html

Doolittle, P. (1994).  Teacher Portfolio Assessment.  This ERIC Digest describes the use of the portfolio as a part of performance based assessment.
http://www.is.wayne.edu/fls/portfoli.htm

Houghton Mifflin's Portfolio Assessment - an overview of the development and uses of portfolio assessment.
http://www.eduplace.com/rdg/res/literacy/assess6.html

Indiana University.  A bibliographic introduction to portfolio assessment assembled from the World Wide Web, ERIC Database, and a variety of other bibliographic resources. Includes article abstracts.
http://www.indiana.edu/~reading/ieo/bibs/portfoli.html

NCLRC. (1997). Portfolio Assessment in the Foreign Language Classroom.  Links to a fully revised manual on portfolio assessment that could be adapted to many disciplines.
http://www.nclrc.org/portfolio/modules.html

Prince George County Maryland's Portfolio Assessment.  Multiple links to establishing and using a portfolio assessment system.
http://www.pgcps.pg.k12.md.us/~elc/portfolio.html

Rogers, G. (2004).  Assessment Planning Resource.  Dr. Gloria Roger's website with links to her assessment planning flow chart, planning process self-assessment, assessment for quality assurance power point presentation, ABET related resources, business and industry assessment processes, assessment rubrics, electronic portfolios, and assessment terminology.
http://www.assessmentplan.com/

Sewell,M,Marczak, M, & Horn, M. The Use of Portfolio Assessment in Evaluation.
http://ag.arizona.edu/fcs/cyfernet/cyfar/Portfo~3.htm