I’m not sure if this is the right section but a few may find this useful.
Sparkfun electronics have produced a tutorial to aid in the design of PCB’s (Eagle, etc) to cut down on errors and other issues when getting them professionally fabricated.
http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=115
Some good stuff there, but their philosophy on labels (i.e. no parts designators) doesn’t really work well for boards which are shared among a DIY community. Our boards need parts designators AND functional labels.
Nice fat traces sure do help with troubleshooting, and they make for a more reliable board.
For those reading this who haven’t clicked the link yet, they offer a rules file for Eagle as a free download, which may be worth checking out.