Expressing Uncertainty of Measurement Results 
From NIST website: Guidelines and perspectives (U.S. and international) on how to express uncertainties.
http://physics.nist.gov/cuu/Uncertainty/index.htmlLab Notebooks
How to record properly for easier reference.
http://www.life.uiuc.edu/mcb/580/lab-notes.html
Error Analysis in the Physical Sciences
A series of documents and exercises intended to discuss how an experimentalist in the physical sciences determines the errors in a measurement. The level is appropriate for beginning university students in the sciences.
http://www.upscale.utoronto.ca/PVB/Harrison/ErrorAnalysis/
