Effective

1. Constructivist Learning

http://lindy.stanford.edu/~treister/elise/constructivism.html

Good basic background.

2. Constructivist Learning Theory

http://www.northside.isd.tenet.edu/cmptecww/Marks%20presentation%20revised/sld025.htm

The largest body of Internet information so far on the topic.

3. Learning Theory

http://wwwcoh.modlang.arizona.edu/inst/edp512s97/learningtheory.html

Another great site on learning theory with lots of links.

Ineffective

1. Re: Behaviorist Constructivism

http://www.ed.asu.edu/aera/aera-lists/erl-l/old/7.97/0015.html

Nothing but a bunch of cliche statements.

2. Constructivist Teacher Education

Building a World of New Understandings

http://www.tandfdc.com/Falmer/construc.htm

Nothing more than a book sales site.

3. Teaching, Learning and Reform in the 21st Century

http://www.northside.isd.tenet.edu/cmptecww/Marks%20presentation%20revised/sld001.htm

Just a site with information on overall reform. Not specific enough.