Just checked out this sample report and it's an excellent example.... of what NOT to do. I don't have time to take the deep dive as I'm getting ready to hit the road, but an executive summary with technical terms is a poor executive summary. Nmap output and other tool output in the report is just bad. That stuff belongs in an appendix, far too much copy and paste here for my liking. I'll try to take the time to followup on this with more explicit examples and recommendations in the next day or two, but this is NOT a good report.
I didn't mean to lead anyone astray. This one from Offensive Security may be a better example:
http://www.offensive-security.com/penetration-testing-sample-report.pdfalso this paper from SANS on writing a report:
http://www.sans.org/reading_room/whitepapers/bestprac/writing-penetration-testing-report_33343