Some Quick Stella models and tutorials
(obtained by using a google search for "Stella Tutorial")
Stella can be obtained from High Peformance Systems
http://www.ncsec.org/cadre2/team11_2/tutorial.htm
http://www.ecsu.k12.mn.us/envision/gradrule/tutorial2/tutbank.html
http://www.ecsu.k12.mn.us/envision/gradrule/tutorial1/tut1flow.html
http://www.clexchange.org/search/cle_docsearch.asp?category=Science
http://www.arch.usyd.edu.au/~joe/tutorials/DDSS/stella-tute-98.html