Guide for writers of lab reports

This looks clear and promising
(review from AMSER):

A General Guide to Writing Scientific Research Reports
This reference provides instructions on how to write scientific reports. Topics include why we write reports, the basic format (introduction, methods and materials, results, and discussion, or 'IMRaD'), how to state a hypothesis, how to set up tables, graphs and figures, and how to write a discussion. There are also links to additional information, including a sample report, and a list of books on scientific writing.
http://www.unc.edu/depts/wcweb/handouts/lab_report_complete.html