Understand your assignment task before you start! Try these resources.
The University of Sydney's First Year Experience series, although a decade old, has some valuable tips for new students.
Mindmaps are diagrams used for mapping out concepts, tasks etc.
They use colour, images and hierarchical grouping of concepts.
Read more about them here.
Some people find them a boon for:
Although originally conceived of as a pen and paper tool, a wealth of free & commercial software applications have been developed.