Intertextuality is the shaping of a text's meaning by another text. Intertextual figures include: allusion, quotation, calque, plagiarism, translation, pastiche and parody (wiki)
All of the texts studied in class over this year will have potential links to another text studied. Sometimes you will be explicitly informed of these connections, but sometimes you will be left to find them on your own - it's these intertextual links that will be the most valuable, because they will be a product of your own critical analysis and evaluation skills. They will also likely be original ideas or readings.
Some elements to look for links in:
ideas/perspectives/themes
values/attitudes/beliefs/ideologies
contexts
genre
characterisation
POV
conflict