Prepare to discuss all aspects of the research process and the specifics of your research. Presentations are meant to give a succinct overview of the research. Incorporate into your presentation a summary of information from all aspects of your paper, including the original research question, a review of past literature on the topic, research methods used and results. Discuss what the limitations and strengths of your study were and how these pertain to research in the field. Talk about what the implications for future research are and what steps other researchers might take to expand on the work you have done.
Strategize how you will handle answering questions during your presentation. Be ready to answer questions whether you are formally defending your thesis or presenting it in a less formal format. Meet with your thesis adviser to specifically discuss what questions could come up. Attend other student's presentations; this is the best way for you to know what to expect. Pay attention to how that student responds to questions and how she presents her materials. Make note of what aspects of her presentation work and which do not.
Practice your presentation. Rehearse it in front of friends or family. Have your audience ask you questions and give you feedback whether your presentation is clear and understandable. Although thesis presentations are often given to an audience of people who have some knowledge of the topic, your presentation should be done in such a way that someone without prior knowledge can understand.