Rocket Mass
Heaters are really great for a
greenhouse. They provide the heat where it is most important while also providing great opportunities for propagation from seed and cutting. I'm not experienced with getting
hot water from a
RMH but it is certainly possible. Check out
this thread for a method of heating water for domestic use via RMH. I focus more on
aquaculture than aquaponics (because I don't like the feeding involved) but this seems like an
appropriate technology to use in order to heat the water.
As for favorite book that's tough because I have a lot of favorite books. Favorite to use, "
Sepp Holzer's Permaculture" followed my Martin Crawford's "Creating a Forest Garden" - favorite that I'm reading right now, Tom Brown jr's "Awakening Spirits"