Hops
See also:
PrideOfRingwood - where does that name really originate?
HopGrowing for some pics on growing your hops in the sourthern hemisphere.
Some hop style/substitution charts:
HopGrowing some pictures of my Hallertau hop plant.
2002 Great Hop Experiment, Oregon Crew Brew.
http://hbd.org/cassriverhomebrewers/brewtool/brewtools_hops.html
Hopunion and their PDF of hop varieties
Hops at Real Beer. Otherwise known as Glenn Tinseth's Hop Page.