Romelle, happy new year to you too. A good starting point is to work out your research questions – in case studies ‘How?’ and ‘Why?’ questions are often best. The methodology itself should facilitate in-depth investigation, look at multiple perspectives about the issue in question, and include a range of methods.
For reading, I would recommend: Stake, R.E. (2005) Qualitative case studies, in: Denzin, N.K. & Lincoln, Y.S. (eds) The Sage Handbook of Qualitative Research, 3rd ed. London: Sage.