Here’s an FAQ from Analog Devices regarding proper grounding techniques. Engineer Walt Kester answers questions with references and schematics to better explain his points. All in all, a very good read that might help you catch stray signals problems in your next project.
Here’s another good one:
Volume 46 – June 2012
Staying Well Grounded
http://www.analog.com/library/analogDialogue/archives/46-06/staying_well_grounded.html
The page linked in the blog entry is Volume-12 in the first 23 Volume set of “Analog Dialog” presented as a 30th Anniversary Archive. Here is a link to the index page:
http://www.analog.com/library/analogDialogue/Anniversary/contents.html
As of October 2012 they’re up to Volume-46:
http://www.analog.com/library/analogDialogue/index.html