You should be able to answer these questions as your read and they will ensure that your summary is 
Abstract
- Is this relevant to my research? How/how not?
- What do I know about the research from the abstract. What questions do I have?
Introduction
- Why did the authors do this study?
- What problem is the study trying to solve?
- How is this research unique?
- How is this research related to my project?
- What other research exists in relation to this topic?
Discussion / Conclusion
- What did the researchers conclude? Why?
- Are the findings unique and supported by other work in the field?
Methods
- How was this research conducted?
Results
- What data did the study produce?
- What major factors could affect the results?
This list adapted from University of New Mexico's Biology 203L: Ecology and Evolution Guide