Hydronic Underfloor Heating: An article in Backwoods Home Magazine by Michael Hackleman, explaining hydronic floor heating. Includes diagrams.
Installing electric in floor heating: An article on how to choose and install in floor heating.
Oikos: Describing the differences between electric radiant heat and hydronic radiant heat systems.
Radiant Design Institute: Illustrations and detailed tutorials for installation of radiant floor heating.
Solar Radiant Floor Heating: Article describing the use of solar energy (air and hydronic warm floors).
Warmup Underfloor Heating: Warmup manufactures electric underfloor heatering. The DIY undertile and electric radiant heating is taped to the floor prior to tiling.