I know Peggy Hall and her book "Get Rid of Boat Odors" has been discussed on here before.
I was just on a Trawler Forum when I saw that she now has a new revised, expanded and updated version available. It is being sold through a sailboat forum store. and here is the link: http://shop.sailboatowners.com/prod.php?53615.
This is a great book and gives invaluable information for getting rid of boat odors, winterizing and re-commissioning your head and fresh water systems.
She now is going more in depth about the laws and regulations of marine MSD's and also how to choose and install a system.
Peggy has been a great help to me in deciding to go with the Purasan type 1 MSD. This no more pump-outs was the best thing I ever did to any boat I have ever owned. It's not legal everywhere, but it is legal in many more places than most would suspect.
I came by boat from Houston, Tx area to Knoxviille, Tn and my Purasan is legal the whole trip. Soon I will be leaving here and heading to Kentucky Lake and the Cumberland River and so far as I have looked, It is legal that whole trip.
Anyway, I highly recommend this book to everyone that owns a boat.