Keep yourself on the straight and narrow when writing your dissertation, not only because illegal practices can land you and your university or college in trouble, but also because you’re likely to get found out and marked down.
You must keep your university regulations to hand as well as any course materials from your tutors about exact requirements.
You must have ethical clearance for your work (where necessary).
You must make sure that your work does not plagiarise any other works. Always check whether a piece is copyrighted before you use it. Make sure to reference quotes and any information you borrow.