I've found this website to be helpful and informative for those new to merles. I thought this might make a good sticky... especially for those who are breeding merles with no knowledge about them. The merle gene can be dangerous if bred without research.
Here is the link:
http://bowlingsite.mcf.com/Genetics/Merle.html
Here is the link:
http://bowlingsite.mcf.com/Genetics/Merle.html