I bought the e-book from: http://www.sailready.com/
Besides other useful information for a beginner, (cruisier in study), the author includes plans to build your own water maker. He suggests that it is half the price of buying a factory model with much greater capacity. So far I have not studied or know much about desalinization units so I can not give a fair evaluation on what I read. If his claims are true, the price of his e-book is worth the money, many times over.
I could cut an paste the plans here, but I think the e-book is copyrighted. That would not be right or fair. Presently (and timely) there is another active thread on this board concerning copy rights.