The following resources may help you as you complete the "focus" stage of your action research:

A Closer Look at the Action Research Process (slides 5-6 on data collection, analysis, and interpretation)
Action Research Guide for Alberta Teachers (dated but still relevant, take a look at Designing a Data Collection Plan and Analyzing the Research Data pgs. 21-29)
Data Collection, Analysis and Interpretation of GTN Action Research projects
Evolving With Evidence (Joyce Valenza discusses tools that may help you collect data.)
Guiding School Improvement with Action Research (Chapter 9, Data Collection)
Say It With Data (eBook requires NCWiseOwl login..This book focuses on evidence based advocacy which is similar to action research. I think much of its content is applicable to action research data as well.)