Paragraph Development
  8 Modes

For an explanation of what makes a good paragraph (Unity, Coherence, A Topic Sentence, and Adequate Development): http://owl.english.purdue.edu/handouts/general/gl_pgrph2.html

For explanations of eight basic modes of developing paragraphs, along with sample paragraphs:
http://www.longleaf.net/ggrow/modes.html

http://www.tameri.com/write/paragraphs.html