Wikipedia defines plagiarism as: "Plagiarism is the practice of (dishonestly) claiming or implying original authorship of material which one has not actually created, such as when a person incorporates material from someone else's work into his own work without attributing it."
How does plagiarism add up in the digital age? Websites come and go....students copy and paste....and voila they have a body of work. You just have to do a search for plagiarism in google and up pops hundreds of companies that now offer their services to help catch those students that choose to "copy and paste" without references. But do the students really understand what plagiarism is? I did a quick survey of a year 10 ICT class and most of them did not. What was interesting was that most of them did not think that putting an image in an assignment they had saved off the Internet without referencing, really was plagiarism. Most felt it was really to do with the text they copied out of books.
Turnitin.com is a company that offers schools an educational suite that consists of plagiarism 
prevention, grade mark, peer review and gradebook. All of these tools are paperless and done online. Most of the plagiarism companies work in the same manner. Instructors upload digital versions of student work and it is checked against thousands of pieces of work in Turnitin database. Then voila...a report is generated letting the instructor know if the work submitted is "clean of plagiarism."
The American Psychological Association a.k.a. APA Format and the Modern Language Association a.k.a. MLA Style are the two main citation styles used in higher education. A university or college will usually support one or the other. Students at a high school/college level should already be familiar with both formats and use them regularly.
A google search can quickly find online resources for written and digital format styles for both APA and MLA. Many universities and colleges and resources and guides online from their libraries.
In this digital age of "copy and paste" I think it is important that students start referencing images, text, music....anything that they can retrieve off of the Internet and use for their work.
Further Reading on Plagiarism and the Digital Age:
http://www.ncte.org/pubs/chron/highlights/122871.htm
http://www.bethel.edu/its/is/teaching-technology/plagiarism/index.html
http://ahe.cqu.edu.au/
