Hodgson, G., Hill, J., Kiene, W., Maun, L., Mihaly, J., Liebeler, J., Shuman, C. and Torres, R. 2006. Instruction Manual. A Guide to Reef Check Monitoring . Reef Check Foundation, Pacific Palisades, California, USA
Reef Check provides excel spread sheets with built in macros for carrying out preliminary data analysis. Pages 31-36 of their manual have illustrated instructions for how to correctly complete the spreadsheets with explanations of the output data.
There is also a chapter discussing data analysis that explains how to interpret the results including the meanings of the standard error and the standard deviation.