When you've logged into the Turnitin system, or if you've just enrolled, you will come through to a screen showing you the list of classes that you're enrolled onto. A class usually equates to a module at Lancaster. In the following screen capture there is only one class, and your instructor (lecturer/tutor) is one T. Lancs99. Each class will typically have a series of assignments, and to get to them, click on the class name - in this case "New Course for 2008-2009":      

This will take you to the list of assignments as shown below. Again, there is only one assignment in this example. BTW, to go back up to the list of classes, click on the "My Classes" link above the location indicator.

To submit, click on the “Submit” icon to the right of the assignment name with the green arrow on it, and the upload dialogue box will appear as shown below:

Fill in your name if it's not already done for you, type in the name that you want to give the file that you're about to upload, and then browse and find the essay that you want to have checked. The types of computer file format that are accepted by Turnitin are shown in the yellow part of the dialogue box. Turnitin will accept an input file up to 20MB, which is an immense size for a piece of text. If your essay file is even a tenth of that size, you might want to take out images or movies embedded in the essay because otherwise it'll take a long time to upload even if it is accepted.

When you click 'upload', Turnitin not only uploads the file, it unpacks it, discards anything that isn't text, and then displays what it's going to test in a window like the one below:

You should check that the contents are those that you want to be tested, and, if so, click on "Submit". The system returns with an acknowledgement and a digital receipt, as shown below:

From here, click on the "go to portfolio" icon surrounded in yellow, and go to the list of documents that you've submitted:

 The portfolio list of essays (only one essay in this portfolio) has links to the report on the essay. The link to the report is actually the percentage figure - the percentage of your text that matches a source on the internet, in on-line journals or in another student essay. The link remains greyed out as shown here until the Turnitin site has processed your essay. This will occur a few minutes after submission, as shown to the left. In the case shown, it's a totally original essay - and so it's returned 0%, which is what you want. The percentage figure will be an active link, and take you to the report. Go to section 5:  "Example anti-plagiarism reports" to see what an essay with problems looks like, and for tips on the sorts of common mistakes that often cause a high degree of matching with the internet.