Years ago a got a pamphlet with the above title from PPMD. I believe it was written by Dr. Alex Werth. I found it fairly easy (well still had to re-read many parts to figure it out) and helpful when learning the genetic side of this. Does PPMD still have this or something like this now?
I have a well worn copy of the guide. The most extensive genetics information geared for laypeople I am familiar with is available from the NIH: http://www.ghr.nlm.nih.gov/BrowseGenes In addition to fact sheets, there are links to additional information. I hope this is helpful.
Here it is..