Cloudy Nights has a couple of good articles. The first is an overview, the second a record of observations of various objects with various filter types.
http://www.cloudynights.com/accessories/filters.htm
http://www.cloudynights.com/howto/filters.htm
http://www.cloudynights.com/accessories/filters.htm
http://www.cloudynights.com/howto/filters.htm
