other great tutorials on the internet
Houdini Tutotials - http://www.vfxhomeland.com/ Ben Watts - C4D and Houdini tutorials - http://benwattsdesign.com/ Particle Skull - Particle Flow and Houdini Tutorials - http://www.pskull.com/ Peter Quint's Houdini tutorials - https://vimeo.com/user2030228