Plagiarism tutorial

This tutorial, developed by the University of Leicester, gives some good examples of what does and does not constitute plagiarism and some very good advice for anyone producing a piece of academic writing, from undergraduate essays to dissertations and theses.
http://www2.le.ac.uk/offices/ssds/sd/ld/resources/study/plagiarism-tutorial
There are subject specific tutorials for Biological Sciences, Geology and more